Question

Hello!
Kindly solve this question with all steps completely..
Que.2 (i) part..
Actually the answer at NCERT is fully calculated and I am getting some other answer.
Kindly help!!

Answer 1

Here is the solution :

In general if the roots of a Quadratic expressiom are and b, then the Quadratic expression will be x² -(a+b)x + ab,

In all the 3 sums, They have given the (a+b) and ab, So it will be easier to substitute the values in them,

(I) Sum = 1/4 = a+b
Product = -1,

=> Quadratic Equation : x² -(1/4)x -1 = 0,
Multiplying 4 on both sides,
=> Quadratic Equation : 4x² - 1x - 4= 0

(II) Sum = √2, = a+b
Product = 1/3 = ab

Quadratic Equation : x² - (√2)x + 1/3 = 0,
Multiplying 3 on Both sides,
=> 3x² -3√2x + 1 = 0,

(III) Sum = 0 = a+b,
Product = √5 = ab,

Quadratic Equation : x² - 0x + √5 = 0,
=> x² - √5 = 0, (or) √5x² - 5 = 0[Multiplied √5]

These are the Quadratic Equations we need !

Therefore : The answers are :
---- (I) : 4x² -1x - 1 = 0,
-----(II) : 3x² - 3√2x + 1 = 0,
------(III) : x² - √5 = 0,

Hope you understand, Have a Great day !
Thanking you, Bunti 360 !!