CBSE > Class 09 > Mathematics | CBSE Board | Homework Help

Given √2 is irrational number.
Let √2 = a / b wher a,b are integers b ≠ 0
we also suppose that a / b is written in the simplest form
Now √2 = a / b ⇒ 2 = a² / b² ⇒ 2b² = a²
∴ 2b² is divisible by 2
⇒ a² is divisible by 2
⇒ a is divisible by 2
∴ let a = 2c
a² = 4c² ⇒ 2b² = 4c² ⇒ b² = 2c²
∴ 2c² is divisible by 2
∴ b² is divisible by 2
∴ b is divisible by 2
∴a are b are divisible by 2 .
this contradicts our supposition that a/b is written in the simplest form
Hence our supposition is wrong
∴ √2 is irrational number.

0Thank You

ANSWER

How to find area of triangle when sides are in ratio?

Posted by Vaishali Sancheti 6 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Shreya Sood 6 years, 2 months ago

We can take the sides x and then we can multiply the finded value of x with the number in ratio.

0Thank You

ANSWER

if A=7-4root3 tan find root a+1/roota

Posted by Anshuldev Dev 6 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

if(×+3,6)= (6,y+2) then the co- ordinates if (x,y) are

Posted by Prity Kumari 6 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

In triangle abc angle a + angle b is equal to 80 degree and Angle b + angle c is equal to 150 degree find the measure of each angle of triangle ABC.

Posted by Pooja Jain 6 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

How can i pass in maths exam . plzz tell me idea

Posted by Gaurav Sen 6 years, 2 months ago

CBSE > Class 09 > Mathematics

3 answers

Ansh Verma 6 years, 2 months ago

Study hard

0Thank You

Harish Kumar 6 years, 2 months ago

Padh ke

1Thank You

Rishav Jha 6 years, 2 months ago

In my exam most of the question were from ch lines and angle , quadrilateral and heron s formula

1Thank You

ANSWER

What are vertically opposite angles.

Posted by Pari Bathla 6 years, 2 months ago

CBSE > Class 09 > Mathematics

2 answers

Ansh Verma 6 years, 2 months ago

When two parralel lines cutting by a third line

0Thank You

Pavan Aarya 6 years, 2 months ago

When 2 lines intersect each other then the angles formed is called vertically opposite angles

2Thank You

ANSWER

What are alternate interior angles,corresponding angles, cointerior angles

Posted by Pari Bathla 6 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

if P + Q + R = 21 and PQ + QR + PR = 21 and pqr = 2 - 1 find the value of P Cube + Q Cube + R cube

Posted by Mahesh S Mahesh S 6 years, 2 months ago

CBSE > Class 09 > Mathematics

0 answers

ANSWER

If x=0 and y=k is a solution of the equation 5x-3y=3 ,find value of k

Posted by Rhutuja Magar 6 years, 2 months ago

CBSE > Class 09 > Mathematics

7 answers

Reno C S 6 years, 2 months ago

K=1

0Thank You

Komal Pankhudi 6 years, 2 months ago

K=1

0Thank You

Ansh Verma 6 years, 2 months ago

K=1

0Thank You

Gaurav Pushola 6 years, 2 months ago

K=1

0Thank You

R Rajendhiran 6 years, 2 months ago

K=1

0Thank You

Abhishek Kumar 6 years, 2 months ago

K=1

0Thank You

Vinesha Nair 6 years, 2 months ago

K=3

0Thank You

ANSWER

ABCD is a parallelogram . Prove that area of BCP=area ofDPQ if BC=CQ

Posted by Avy Avs 6 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Sia ? 6 years, 2 months ago

Given : ABCD is a parallelogram.
BC=CQ.

To prove :
ar(ΔBCP)=ar(ΔDPQ)

Construction :
Join AC
Proof :
ar(ΔBPC) = ar (ΔAPC) [Triangles on the same base and between same parallels ]

Similarly ,
ar(ΔADC) = ar(ΔADQ) [Triangles on the same base and between same parallels ]

ar(ΔADC) = ar(ΔADP) +ar(ΔAPC)
ar(ΔADQ) = ar(ΔADP) + ar(ΔDPQ)

ar(ΔADC) = ar(ΔADQ) and ,
ar(ΔADP) is common.

{tex}\therefore{/tex} ar(ΔAPC) = ar(ΔDPQ)

But ,
ar(ΔAPC) = ar(ΔBPC)

∴ ar(ΔBPC) = ar(ΔDPQ)
Hence ,proved.

1Thank You

ANSWER

if x²+y²=30 xy=5 then x⁴-y⁴=?

Posted by Gulafshan Nayeem 6 years, 2 months ago

CBSE > Class 09 > Mathematics

1 answers

Ankit Raj 6 years, 2 months ago

Since, x² + y² = 30 ____________(1) & xy = 5 we know that, (x + y)² = x² + y² + 2xy (x + y)² = 30 + 2×5 (x + y)² = 40 (x + y) = √40___________(2) Again (x - y)² = x² + y² - 2xy (x - y)² = 30 - 2×5 (x - y)² = 20 (x - y) = √20____________(3) therefore, (x⁴ - y⁴) = (x² - y²)(x² + y²) = (x - y)(x + y)(x² + y²) = √20×√40×30 = 20√2×30 (x⁴ - y⁴) = 600√2.

0Thank You

ANSWER

if x²+y²=30 then x⁴-y⁴=?

Posted by Gulafshan Nayeem 6 years, 2 months ago

CBSE > Class 09 > Mathematics