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Tan 20 ta40 tan 8o is equal to tan 60 prove

Posted by Shalini Rajput 6 years, 11 months ago

1 answers

Pihu Saini 6 years, 11 months ago

Given, tan 20 * tan 40 * tan 80 = tan 40 * tan 80 * tan 20 = [{sin 40 * sin 80}/{cos 40 * cos 80}] *(sin 20/cos 20) = [{2 * sin 40 * sin 80}/{2 * cos 40 * cos 80}] *(sin 20/cos 20) = [{cos 40 - cos 120}/{cos 120 + cos 40}] *(sin 20/cos 20) = [{cos 40 - cos (90 + 30)}/{cos (90 + 30) + cos 40}] *(sin 20/cos 20) = [{cos 40 + sin30}/{-sin30 + cos 40}] *(sin 20/cos 20) = [{(2 * cos 40 + 1)/2}/{(-1 + cos 40)/2}] *(sin 20/cos 20) = [{2 * cos 40 + 1}/{-1 + cos 40}] *(sin 20/cos 20) = [{2 * cos 40 * sin 20 + sin 20}/{-cos 20 + cos 40 * cos 20}] = (sin 60 - sin 20 + sin 20)/(-cos 20 + cos 60 + cos 20) = sin 60/cos 60 = tan 60...

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Tan 20 tan 6o tan 80 is equal tan 60

Posted by Shalini Rajput 5 years, 8 months ago

CBSE > Class 10 > Mathematics

1 answers

Sia ? 6 years, 4 months ago

LHS = tan 20° tan 40° tan 80° {tex}=\frac{\sin 20^{\circ} \sin 40^{\circ} \sin 80^{\circ}}{\cos 20^{\circ} \cos 40^{\circ} \cos 80^{\circ}}{/tex}
{tex}=\frac{\left(2 \sin 20^{\circ} \sin 40^{\circ}\right) \sin 80^{\circ}}{\left(2 \cos 20^{\circ} \cos 40^{\circ}\right) \cos 80^{\circ}}{/tex}
{tex}=\frac{\left(\cos 20^{\circ}-\cos 60^{\circ}\right) \sin 80^{\circ}}{\left(\cos 60^{\circ}+\cos 20^{\circ}\right) \cos 80^{\circ}}{/tex} [{tex}\because{/tex} 2 sin a sin b = cos (a-b) - cos (a+b), 2 cos a cos b = cos (a+b) + cos (a-b)]
{tex}=\frac{\sin 80^{\circ} \cos 20^{\circ}-(1 / 2) \sin 80^{\circ}}{(1 / 2) \cos 80^{\circ}+\cos 80^{\circ} \cos 20^{\circ}}{/tex} [ {tex}\because \cos\;60^o=\frac12{/tex}]
{tex}=\frac{2 \sin 80^{\circ} \cos 20^{\circ}-\sin 80^{\circ}}{\cos 80^{\circ}+2 \cos 80^{\circ} \cos 20^{\circ}}{/tex}
{tex}=\frac{\sin 100^{\circ}+\sin 60^{\circ}-\sin 80^{\circ}}{\cos 80^{\circ}+\cos 100^{\circ}+\cos 60^{\circ}}{/tex}[{tex}\because{/tex} 2 sin a cos b = sin (a+b) + sin (a-b)]
{tex}=\frac{\sin \left(180^{\circ}-80^{\circ}\right)+\sin 60^{\circ}-\sin 80^{\circ}}{\cos 80^{\circ}+\cos \left(180^{\circ}-80^{\circ}\right)+\cos 60^{\circ}}{/tex}
{tex}=\frac{\sin 80^{\circ}+\sin 60^{\circ}-\sin 80^{\circ}}{\cos 80^{\circ}-\cos 80^{\circ}+\cos 60^{\circ}}{/tex} {tex}=\frac{\sin 60^{\circ}}{\cos 60^{\circ}}{/tex} = tan 60° = RHS

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If I got 15/80 in maths of board then will i pass

Posted by Jas K?‍? 5 years, 8 months ago

CBSE > Class 10 > Mathematics

7 answers

Rohit Sahani??? 6 years, 11 months ago

No bro u will fail if u get 15 marks in maths. Passing marks=27out of 80.passing %=33.

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Ashish Kumar 6 years, 11 months ago

Out of 100 marks 20 will be given by school on oral,PT, etc. To pass only 33%out of 100 you will have to score. Be patient!!

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Avinash Saigal 6 years, 11 months ago

If I suggest then Just be positive .Don't think negative that you will get less marks in board exams.????

3Thank You

Jas K?‍? 6 years, 11 months ago

Practical means

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Ashish Kumar 6 years, 11 months ago

You may if you will get 15+ marks in Practical!!

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Jas K?‍? 6 years, 11 months ago

But I am too weak in maths

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Janice Dias 6 years, 11 months ago

No you need minimum 30 /80

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A bag contains 15 white balls and some black balls. If the probability of drawing a black ball from the bag is thrice that of drawing a white ball find the number of black balls in the bag

Posted by Yogesh Parihar 6 years, 11 months ago

CBSE > Class 10 > Mathematics

1 answers

Lavina Rajput ??? 6 years, 11 months ago

No. of white balls=15 let the no. of black balls = x probability of drawing a white ball = 15/(15+x) probability of drawing a black ball = x/(15+x) According to given condition- x/(15+x)=3*15/(15+x) x=3*15 =45 therefore the no. of black balls = 45

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Find the sum of all two digit no. Which when dividd by 4 yield 3 as remainder

Posted by Durgesh Kumar 6 years, 11 months ago

CBSE > Class 10 > Mathematics

1 answers

Murari Barnwal 6 years, 11 months ago

1254

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Atraveller travel first half distanceof his journey is same speed and remaining half distance is15km/hmore than the first speed.the average speed of the journey was 36 km find the speed in each journey

Posted by Neethu Jinish 6 years, 11 months ago

CBSE > Class 10 > Mathematics

0 answers

ANSWER

(k-12)x+2(k-12)x+2=0

Posted by Khawa Khan 6 years, 11 months ago

CBSE > Class 10 > Mathematics

1 answers

Durgesh Kumar 5 years, 8 months ago

Anewer

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x/0.125 = x/0.75 + 20

Posted by Megha Mishra 6 years, 11 months ago

CBSE > Class 10 > Mathematics

0 answers

ANSWER

During a trip, Francine traveled x percent of the total distance at an average speed of 40 miles per hour and the rest of the distance at an average speed of 60 miles per hour. In terms of x, what was Francine's average speed for the entire trip? See if you can apply that knowledge to this question.

Posted by Kaushik Raj 6 years, 11 months ago

CBSE > Class 10 > Mathematics

0 answers

ANSWER

Formula pf Sn

Posted by Harsh Chahal 6 years, 11 months ago

CBSE > Class 10 > Mathematics

3 answers

Augustya Singh 6 years, 11 months ago

n/2(2a+(n-1)d)

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Shreyanka Das 6 years, 11 months ago

Another formula for Sn is n/2(a+an).............

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D.J Alok 6 years, 11 months ago

Sn= n/2{2a+(n-1)d}

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The numerator of is 3 less than is denominator.If 2 is added both of its numerator then the sum of the new fractions and original fraction is 29/20.find the number.

Posted by Rajni Shah 6 years, 11 months ago

CBSE > Class 10 > Mathematics

3 answers

Anshika & Aliens???? 6 years, 11 months ago

11x^2 -98x-120=0 solve this u will get answer

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Rajni Shah 6 years, 11 months ago

7/10

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Rajni Shah 6 years, 11 months ago

7/1

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A melallic cylinder has radius 3cm and height 5cm. To reduce uts weight ,a conicial hole is drilled in a cylinder .the conicial whole had radius 1.5cm.and its depth is 8/9cm. Calculate the ratio of volume of metal left in cylinder to the metal taken out the conicual shape.

Posted by Avaneesh Sharma Mdjssv 6 years, 11 months ago

CBSE > Class 10 > Mathematics

1 answers

Anshika & Aliens???? 6 years, 11 months ago

Cylinder volume is 141.42 After removing the conical metal it is 139.33

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If A(a,2) , B (-3,-a) ,c (7,-5) are co linear .find n

Posted by Digraj Chouhan 6 years, 4 months ago

CBSE > Class 10 > Mathematics

1 answers

Sia ? 6 years, 4 months ago

Since the points are collinear, then,
Area of triangle = 0
{tex}\frac { 1 } { 2 } \left[ x _ { 1 } \left( y _ { 2 } - y _ { 3 } \right) + x _ { 2 } \left( y _ { 3 } - y _ { 1 } \right) + x _ { 3 } \left( y _ { 1 } - y _ { 2 } \right) \right] = 0{/tex}
{tex}\frac { 1 } { 2 } [ x ( - 4 + 5 ) + ( - 3 ) ( - 5 - 2 ) + 7 ( 2 + 4 ) ] = 0{/tex}
x + 21 + 42 = 0
x = -63

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Theorem of BPT

Posted by Sailesh Gupta 6 years, 11 months ago

CBSE > Class 10 > Mathematics

1 answers

Parneet Kaur Dhaliwal 6 years, 11 months ago

If a line is drawn parallel to one side of a triangle to intersect the other two sides in distinct points, the other two sides are divided in the same ratio

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Prove Pythagoras thoerm

Posted by Avnish Pandey 6 years, 11 months ago

CBSE > Class 10 > Mathematics

2 answers

D.J Alok 6 years, 11 months ago

Proved in ncert.....

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Parneet Kaur Dhaliwal 6 years, 11 months ago

In a right ?, the sq. of hypotenuse is equal to the sum of the sq. of the other two sides

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Find a,so that (3,a) lies on the line represental by 2x-3y-5=0 also find the co-ordinat of the points where the line cuts x-axis

Posted by Digraj Chouhan 6 years, 6 months ago

CBSE > Class 10 > Mathematics

1 answers

Sia ? 6 years, 6 months ago

(3, a) lies on 2x - 3y - 5 = 0
So, 2 {tex}\times{/tex} 3 - 3y - 5 = 0
1 = 3a
a = {tex}\frac 13{/tex}
2x - 3y - 5 = 0 cuts the x-axis at (x, 0).
{tex}\therefore{/tex} 2x -5 = 0 or, x = {tex}\frac 52{/tex}
or, Point is {tex}\left( \frac { 5 } { 2 } , 0 \right){/tex} .

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if two vertical of Qudaterial ∆A(3,0) and (6,0) find third vertex

Posted by Digraj Chouhan 6 years, 11 months ago

CBSE > Class 10 > Mathematics

4 answers

Parneet Kaur Dhaliwal 6 years, 11 months ago

X=9/2 and Y=0 therefore (9/2,0)

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Digraj Chouhan 6 years, 11 months ago

Chapter 7 coordinate geometry

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Parneet Kaur Dhaliwal 6 years, 11 months ago

Sorry wrong ans

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Parneet Kaur Dhaliwal 6 years, 11 months ago

12 units

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Find perimeter of ∆ with verticals A(0,4) ,B(0,0) and c(3,0)

Posted by Digraj Chouhan 6 years, 11 months ago

CBSE > Class 10 > Mathematics

1 answers

Parneet Kaur Dhaliwal 6 years, 11 months ago

12 units

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If cosA=2/5, find the value of 4 +4tan²A

Posted by Parneet Kaur Dhaliwal 6 years, 11 months ago

CBSE > Class 10 > Mathematics

2 answers

Anjali Kumari? 6 years, 11 months ago

First of all u have to find ( Perpedicular) by pythagoras theorem. Value of P is root21. Then 4 + 4×(root21/2)^2 4+ 4×( 21/4) 4+21 25 Ans

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Anjali Kumari? 6 years, 11 months ago

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Plz tell me how i do ch-9 of maths osme diagram ke galti Ho jati hay or fir Sara que galt

Posted by Parneet Kaur Dhaliwal 6 years, 11 months ago

CBSE > Class 10 > Mathematics

3 answers

Jot Virk?♠ 6 years, 11 months ago

Statement ko point to point and word to word padho aur according to given points steps to step figure banate raho and figure bilkul correct banagi

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Parneet Kaur Dhaliwal 6 years, 11 months ago

Thanks

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Anshika & Aliens???? 6 years, 11 months ago

Learn from CBSE guide may it help u i had learn all difficult chapters from this site this is really helpful ??

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Find the value of a for which point p(a/3,2) is the midpoint of the line segment joining the points Q(-5,4) and R(-1,0)

Posted by Deeptesh Duklan 6 years, 11 months ago

CBSE > Class 10 > Mathematics

1 answers

Anshika & Aliens???? 6 years, 11 months ago

A=-9

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What is the maximum value of 1/cosecQ

Posted by Parneet Kaur Dhaliwal 6 years, 11 months ago

CBSE > Class 10 > Mathematics

1 answers

Anshika & Aliens???? 6 years, 11 months ago

1.because 1/cosec=sin.In trigonometry ratios table the maximum value for sin is 1

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CosA -sinA+ 1÷ cosA +sinA -1=cosecA+ cotA

Posted by Jot Virk?♠ 6 years, 11 months ago

CBSE > Class 10 > Mathematics

3 answers

Jot Virk?♠ 6 years, 11 months ago

By which identity

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Shivam Balodi 6 years, 11 months ago

First divide each term by SinA and then solve it by trignometric identity

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Jot Virk?♠ 6 years, 11 months ago

Plz solve this problem fastly

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√3/2=3/h

Posted by Akash Maurya 6 years, 11 months ago

CBSE > Class 10 > Mathematics

3 answers

Shivam Balodi 6 years, 11 months ago

2√3

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Anshika & Aliens???? 6 years, 11 months ago

If u will simplify than answer will be 2✓3

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Anshika & Aliens???? 6 years, 11 months ago

H=6✓3/3

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Plz help If 7 times of 7th term of an A.P is equal to 11 times of 11th term of an A.P. then find the value of 18th term

Posted by Bahubali Gaming 6 years, 11 months ago

CBSE > Class 10 > Mathematics

3 answers

Anshika & Aliens???? 6 years, 11 months ago

7th term = (a+6d) 11th term = (a+10d) (a+6d)7 since 7th term of the ap is 7 times and the same for 11th term (a+6d)7=(A+10d)11 (given) 7a + 42d =11a +110d (on solving) 7a - 11a = 110d - 42d -4a = -68d a= -17d we know 18th term = (a+17d)................................. (i) now we substitute the value of a in (i) which emplies, -17d + 17d = 0 hence prove..

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Sumit Rajput 6 years, 11 months ago

What is a sun light

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Avinash Saigal 6 years, 11 months ago

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Please tell me all the areas and perimeters of all the shapes please please please please please

Posted by Anshika & Aliens???? 6 years, 11 months ago

CBSE > Class 10 > Mathematics

2 answers

Parneet Kaur Dhaliwal 6 years, 11 months ago

So simple

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Parneet Kaur Dhaliwal 6 years, 11 months ago

Yar my cbse guides me na math sub. Khol osme revision notes pade he os se padh le

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In an AP the sum of first n term is √3n/2+13n/2 find the 25th term

Posted by Jannat Jahan 6 years, 11 months ago

CBSE > Class 10 > Mathematics

0 answers

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(p-3)x+3y=p px+py=12

Posted by Payal Chatterjee 6 years, 6 months ago

CBSE > Class 10 > Mathematics

1 answers

Sia ? 6 years, 6 months ago

Consider equations (p - 3)x + 3y = p
and px + py = 12
For infinitely many solutions,
{tex}\frac{p - 3}{p}{/tex} = {tex}\frac{3}{p}{/tex} = {tex}\frac{p}{12}{/tex}...........(i)
Consider, {tex}\frac{3}{p}{/tex} = {tex}\frac{p}{12}{/tex} {tex}\Rightarrow{/tex} p² = 36 {tex}\Rightarrow{/tex} p = {tex}\pm{/tex}6
For p = 6, from (i) {tex}\frac{3}{6}{/tex} = {tex}\frac{3}{6}{/tex} = {tex}\frac{6}{12}{/tex}, true
For p = -6, from (i) {tex}\frac{-9}{-6}{/tex} = {tex}\frac{3}{-6}{/tex} = {tex}\frac{-6}{12}{/tex}, false.
Hence, for p = 6, pair of linear equations has infinitely many solutions.

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A peacock is sitting on the top of a pillar which is 9m high.From a point 27m away from the bottom of the pillar.a snake is coming to its hole at the base of the pillar. Seeing the snake the peacock pounce on it. If their speed are equal,at what distance from the the hole is the snake caught.

Posted by Mohammad Amaan 6 years, 11 months ago

CBSE > Class 10 > Mathematics

1 answers

Avinash Saigal 6 years, 11 months ago

Let the distance covered by the peacock be AC = x m Hence the distance covered by the snake is DC = x m In right ΔABC, by Pythagoras theorem we have AC2 = AB2 + BC2 x2 = 92 + (27 – x)2 ⇒ x2 = 81 + 729 – 54x + x2 ⇒ 54x = 810 ∴ x = 15....... Thank you???

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Find the common difference of the AP 1/p ,1-P/P ,1-2P / P ...…...

Posted by Sadhana Sadhana 6 years, 11 months ago

CBSE > Class 10 > Mathematics