Question

if one root of equation 2xsq- 8x-m =0is 3/2 find the other root of quadratic equation

Answer 1

Solution :

Given Quadratic equation

2x² - 8x - m = 0 .

It is given that , 3/2 one root of the

equation .

substitute x = 3/2 in the equation, we

get

2(3/2)² - 8(3/2) - m = 0

=> 9/2 - 24/2 - m = 0

=> ( 9 - 24 )/2 - m = 0

=> -15/2 = m

Therefore ,

m = -15/2

Now ,

Equation becomes ,

2x² - 8x + 15/2 = 0 Compare this

with ax² + bx + c = 0 , we get

a = 2 , b = -8 , c = 15/2

Let the second root = p

first root = 3/2

product of the roots = c/a

=> ( 3/2 ) × p = ( 15/2 )/2

=> p = ( 15 × 2 )/( 2 × 2 × 3 )

=> p = 5/2

Therefore ,

Second root ( p ) = 5/2

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