CBSE > Class 10 > Mathematics | CBSE Board | Homework Help

Let take that 3 + 2√5 is a rational number.
So we can write this number as
3 + 2√5 = a/b
Here a and b are two co prime number and b is not equal to 0
Subtract 3 both sides we get
2√5 = a/b – 3
2√5 = (a-3b)/b
Now divide by 2 we get
√5 = (a-3b)/2b
Here a and b are integer so (a-3b)/2b is a rational number so √5 should be a rational number But √5 is a irrational number so it contradict the fact
Hence result is 3 + 2√5 is a irrational number

0Thank You

Alka Sharma 6 years, 2 months ago

Let 3+2√5 be a rational no. 3+√5=a/b (a & b are co-prime no.) √5=a-3b/b (we know that √5 is a irrational no) This contradict the fact that 3+√5 is a irrational no.

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ANSWER

should we write constructions steps even if it is not mentioned to write

Posted by Rahul Pawar 6 years, 2 months ago

CBSE > Class 10 > Mathematics

3 answers

??Geetha Sree ?? 6 years, 2 months ago

Hey , If the question comes for 3 or 4 marks u need to write the steps. If it is for 1 or 2 marks u don't need to. Of course constructions wouldn't come for 1 or 2 marks . So u need to write the steps.

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Itika Singhal 6 years, 2 months ago

No need...You can draw rough diagram...

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Alka Sharma 6 years, 2 months ago

No if you write construction steps and there is no need to write so you will lose your marks if there is negative marking

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ANSWER

A rational no. Between √2 and √6??

Posted by Mr.Xxx ??? 6 years, 2 months ago

CBSE > Class 10 > Mathematics

13 answers

Pk . 6 years, 2 months ago

Good morning sis...

1Thank You

Aadya Singh ? 6 years, 2 months ago

Hii..

1Thank You

Dr. Sanskari ?‍⚕️?‍⚕️ 6 years, 2 months ago

Hloooo

1Thank You

Dr. Sanskari ?‍⚕️?‍⚕️ 6 years, 2 months ago

4/2.....=2

0Thank You

Dr. Sanskari ?‍⚕️?‍⚕️ 6 years, 2 months ago

1Thank You

Rudransh Agarwal 6 years, 2 months ago

1.5

0Thank You

Aadya Singh ? 6 years, 2 months ago

Thanks bro...and good morning ?

3Thank You

Pk . 6 years, 2 months ago

Bilkul ho sakta hai sis.......i agree with you????

1Thank You

Aadya Singh ? 6 years, 2 months ago

??To 1.78 nhi ho sakta kya...aisa kisne bola..?? ???

2Thank You

Mr.Xxx ??? 6 years, 2 months ago

2Thank You

Mr.Xxx ??? 6 years, 2 months ago

√4 is between √2 and √6.........√4=2 so 2 is a rational number

1Thank You

Mr.Xxx ??? 6 years, 2 months ago

Nope

1Thank You

Aadya Singh ? 6 years, 2 months ago

1.78

2Thank You

ANSWER

In an equilateral ABCD the diagonal AC bisect C prove that the diagonal BD is parallel to the tangent at A to the circle passing through A B C and D

Posted by Mazuali Mazuali 6 years, 2 months ago

CBSE > Class 10 > Mathematics

1 answers

Himanshu Gupta 6 years, 2 months ago

Use theorem 10.2

0Thank You

ANSWER

Hcf of 8392

Posted by Siva Kumar 6 years, 2 months ago

CBSE > Class 10 > Mathematics

1 answers

Sam Pandey 6 years, 2 months ago

HCF can be obtain by 2 no. So givi other no. Then we can give u ans

1Thank You

ANSWER

PythagorasTheorem

Posted by Rakesh Kumar 6 years, 2 months ago

CBSE > Class 10 > Mathematics

1 answers

Vanshika . 6 years, 2 months ago

(Hypotenuse)^2 = one side ^2 + other side ^2

1Thank You

ANSWER

If nth term of an AP is an+b then its common difference

Posted by Vinayak Mishra 6 years, 2 months ago

CBSE > Class 10 > Mathematics

1 answers

Yogita Ingle 6 years, 2 months ago

We are to find the common difference of an A.P. if its n-th term is given by (an + b).

The n-th term of the A.P. is

{tex}a_n=an+b.{/tex}

Therefore, the (n+1)-th term of the A.P. will be

{tex}a_{n+1}=a(n+1)+b.{/tex}

We know that the common difference of an A.P. means the difference between two consecutive terms, so

{tex} {common difference},~d=a_{n+1}-a_n=(an+a+b)-(an+b)=a.{/tex}

Thus, the required common difference is 'a'.

1Thank You

ANSWER

Find the area of the quadrilateral ABCD, the co-ordinates of whose vertices are A(-3,2)B, (5,4)C,(7,-6)D,(-5,-4)

Posted by Anshika - 6 years, 2 months ago

CBSE > Class 10 > Mathematics

6 answers

M.......... Duhan 6 years, 2 months ago

In ABC=1/2{-3(4+6)+5(-6-2)+7(2-4)} =1/2{-3*10+5*-8+7*-2}=42 sq.unit???? Now in ACD=38 sq.unit ..........so,area of quadrilateral=42+38=80 sq.unit.??

2Thank You

Anshika - 6 years, 2 months ago

How the answer is 80

1Thank You

Megha Agarwal 6 years, 2 months ago

1Thank You

Anshika - 6 years, 2 months ago

☹️?

1Thank You

Anshika - 6 years, 2 months ago

Thank you But the answer is 80

1Thank You

Piyush Kr.?? 6 years, 2 months ago

1Thank You

ANSWER

Without using table, evaluate Sin(50- A) - cos(40-A)+ tan 1°tan10°tan20°tan70°tan80°tan90°

Posted by Avni Gupta 6 years, 2 months ago

CBSE > Class 10 > Mathematics

3 answers

M.......... Duhan 6 years, 2 months ago

Question is not correct. This question has also come in our exam.at last there is tan89°

0Thank You

Avni Gupta 6 years, 2 months ago

Question is correct

1Thank You

P. Varsha 6 years, 2 months ago

Pls once check this question is it write

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ANSWER

15 cot a= 8 gind sina and seca

Posted by Hari Shankar 6 years, 2 months ago

CBSE > Class 10 > Mathematics

3 answers

Arpit Srivastava 6 years, 2 months ago

sinA=15/17,secA=17/8

0Thank You

Avni Gupta 6 years, 2 months ago

SinA = 15/17 SecA =17/8

0Thank You

Piyush Kr.?? 6 years, 2 months ago

sinA=8/17 and secA=17/15

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ANSWER

To find Euclid's division algorithm to find the HCF of:135 & 225

Posted by Ankita Srivastava 6 years, 2 months ago

CBSE > Class 10 > Mathematics

2 answers

Ankit Garg 6 years, 2 months ago

45 225=135×1+90and135=90×1+45and90=45×2+0

0Thank You

Jagjit Gill 6 years, 2 months ago

Divide 135 by 225

3Thank You

ANSWER

What is the distance between the points A(sinø-cosø,0)and B(0,sinø+cosø)?

Posted by Nandini Kumari 6 years, 2 months ago

CBSE > Class 10 > Mathematics

1 answers

Piyush Kr.?? 6 years, 2 months ago

I think answer should be √2

1Thank You

ANSWER

Prove that the tangents drawn at the ends of a diameter of a circle are parallel

Posted by Shikha Kashyap 6 years, 2 months ago

CBSE > Class 10 > Mathematics

1 answers

Piyush Kr.?? 6 years, 2 months ago

Let a circle with centre 'O' and diameter A'O'B.... Now two tangents RS intersecting at A and PQ intersecting at B is drawn... Since angle BAR and angle ABP is equal to 90°....and we know that one and only one perpendicular line can be drawn and it acts as a transversal and both corresponding angles are 90° hence tangents RS and PQ are parallel...

1Thank You

ANSWER

AB = 36CM and, M is the midpoint of AB. AB touches three semicircles with diameter AC and MB. Find the area of the shaded region.

Posted by Ajit Kumar 6 years, 2 months ago

CBSE > Class 10 > Mathematics