Advertisements
Advertisements
प्रश्न
If a2 + b2 + c2 = 16 and ab + bc + ca = 10, find the value of a + b + c.
Advertisements
उत्तर
We know that,
`(a + b + c)^2 = a^2 + b^2 + c^2 + 2(ab + bc + ca)`
`=> (a + b + c)^2 = 16 + 2(10)` [`∵ a^2 + b^2 + c^2 = 16` and ab + bc + ca = 10]
`=> (a + b + c)^2 = 16 + 20`
`=> (a + b + c) = sqrt36`
`=> a + b + c = +-6`
APPEARS IN
संबंधित प्रश्न
Evaluate the following product without multiplying directly:
95 × 96
Factorise the following:
8a3 + b3 + 12a2b + 6ab2
Without actually calculating the cubes, find the value of the following:
(–12)3 + (7)3 + (5)3
Evaluate the following using identities:
`(2x+ 1/x)^2`
Evaluate the following using identities:
(399)2
If 3x - 7y = 10 and xy = -1, find the value of `9x^2 + 49y^2`
Simplify the following products:
`(x/2 - 2/5)(2/5 - x/2) - x^2 + 2x`
Evaluate of the following:
(103)3
If x = 3 and y = − 1, find the values of the following using in identify:
\[\left( \frac{x}{7} + \frac{y}{3} \right) \left( \frac{x^2}{49} + \frac{y^2}{9} - \frac{xy}{21} \right)\]
Find the following product:
(3x + 2y + 2z) (9x2 + 4y2 + 4z2 − 6xy − 4yz − 6zx)
The product (x2−1) (x4 + x2 + 1) is equal to
Use identities to evaluate : (97)2
Use identities to evaluate : (998)2
If a + `1/a`= 6 and a ≠ 0 find :
(i) `a - 1/a (ii) a^2 - 1/a^2`
Expand the following:
(2x - 5) (2x + 5) (2x- 3)
If x + y = 9, xy = 20
find: x - y
Expand the following:
`(1/x + y/3)^3`
Find the following product:
`(x/2 + 2y)(x^2/4 - xy + 4y^2)`
