Advertisements
Advertisements
प्रश्न
If a − b = 5 and ab = 12, find the value of a2 + b2
Advertisements
उत्तर
We have to find the value `a^2 +b^2`
Given a-b = 5, ab = 12
Using identity `(a - b)^2 = a^2 - 2ab +b^2`
By substituting the value of a-b = 5 ,ab = 12 we get ,
`(5)^2 = a^2 +b^2 - 2 xx 12`
`5 xx 5 = a^2 +b^2 - 2 xx 12`
`25 = a^2 +b^2 -24`
By transposing – 24 to left hand side we get
`25 + 24 = a^2 +b^2`
`49 = a^2 +b^2`
Hence the value of `a^2 +b^2` is 49.
APPEARS IN
संबंधित प्रश्न
Use suitable identity to find the following product:
`(y^2+3/2)(y^2-3/2)`
If a2 + b2 + c2 = 16 and ab + bc + ca = 10, find the value of a + b + c.
If a + b + c = 9 and ab + bc + ca = 23, find the value of a2 + b2 + c2.
Evaluate of the following:
(9.9)3
Find the value of 64x3 − 125z3, if 4x − 5z = 16 and xz = 12.
If \[x^4 + \frac{1}{x^4} = 119\] , find the value of \[x^3 - \frac{1}{x^3}\]
If x = 3 and y = − 1, find the values of the following using in identify:
(9y2 − 4x2) (81y4 +36x2y2 + 16x4)
Find the following product:
(3x + 2y + 2z) (9x2 + 4y2 + 4z2 − 6xy − 4yz − 6zx)
If \[x + \frac{1}{x}\] 4, then \[x^4 + \frac{1}{x^4} =\]
The product (x2−1) (x4 + x2 + 1) is equal to
If 49a2 − b = \[\left( 7a + \frac{1}{2} \right) \left( 7a - \frac{1}{2} \right)\] then the value of b is
Use identities to evaluate : (97)2
Use the direct method to evaluate :
`("z"-2/3)("z"+2/3)`
Expand the following:
(3x + 4) (2x - 1)
Simplify by using formula :
(2x + 3y) (2x - 3y)
Evaluate, using (a + b)(a - b)= a2 - b2.
999 x 1001
Simplify:
(x + y - z)2 + (x - y + z)2
Simplify:
(1 + x)(1 - x)(1 - x + x2)(1 + x + x2)
Factorise the following:
4x2 + 20x + 25
If a + b + c = 9 and ab + bc + ca = 26, find a2 + b2 + c2.
