Advertisements
Advertisements
प्रश्न
If a + b + c = 9 and ab + bc + ca = 23, find the value of a2 + b2 + c2.
Advertisements
उत्तर
We know that,
`(a + b + c)^2 = a^2 + b^2 + c^2 + 2(ab + bc + ca)`
`=> (9)^2 = a^2 + b^2 + c^2 + 2(23)`
`=> 81 = a^2 + b^2 + c^2 + 46` [∵ a + b + c = 9 and (ab + bc + ca = 23)]
`=> a^2 + b^2 + c^2 = 81 - 46`
`=> a^2 + b^2 + c^2 = 35`
APPEARS IN
संबंधित प्रश्न
Use suitable identity to find the following product:
`(y^2+3/2)(y^2-3/2)`
Evaluate the following product without multiplying directly:
104 × 96
Factorise the following using appropriate identity:
4y2 – 4y + 1
Expand the following, using suitable identity:
(x + 2y + 4z)2
Verify:
x3 + y3 = (x + y) (x2 – xy + y2)
What are the possible expressions for the dimensions of the cuboids whose volume is given below?
| Volume : 12ky2 + 8ky – 20k |
Simplify the following:
0.76 x 0.76 - 2 x 0.76 x 0.24 x 0.24 + 0.24
Simplify the following products:
`(x^3 - 3x^2 - x)(x^2 - 3x + 1)`
Simplify the following products:
`(2x^4 - 4x^2 + 1)(2x^4 - 4x^2 - 1)`
Evaluate of the following:
(598)3
If x = 3 and y = − 1, find the values of the following using in identify:
\[\left( \frac{x}{y} - \frac{y}{3} \right) \frac{x^2}{16} + \frac{xy}{12} + \frac{y^2}{9}\]
The product (a + b) (a − b) (a2 − ab + b2) (a2 + ab + b2) is equal to
Expand the following:
(2p - 3q)2
Simplify by using formula :
(5x - 9) (5x + 9)
Simplify by using formula :
(2x + 3y) (2x - 3y)
If `"a" + 1/"a" = 6;`find `"a"^2 - 1/"a"^2`
Simplify:
(x + y - z)2 + (x - y + z)2
Simplify:
(x + 2y + 3z)(x2 + 4y2 + 9z2 - 2xy - 6yz - 3zx)
Simplify:
(2x - 4y + 7)(2x + 4y + 7)
