Advertisements
Advertisements
प्रश्न
If a + b + c = 0, then \[\frac{a^2}{bc} + \frac{b^2}{ca} + \frac{c^2}{ab} =\]
पर्याय
0
1
-1
3
Advertisements
उत्तर
We have to find `a^2/(bc)+ b^2 /(ca) +c^2 /(ab)`
Given a + b + c = 0
Using identity `a^3 +b^3 +c^3 -3abc = (a+b+c)(a^2 +b^2 +c^2 -ab -bc -ca)`
`a^3 +b^3 +c^3 -3abc = 0 (a^2 +b^2 +c^2 -ab -bc -ca)`
`a^3 +b^3 +c^3 - 3abc = 0 `
`a^3 +b^3 + c^3 = 3abc`
`a^3 /(abc)+ b^3/(abc) +c^3 /(abc ) = 3`
`((a xx a xx a)/(a xx b xx c))+ ((b xx b xx b)/(a xx b xx c))+((c xx c xx c)/(a xx b xx c)) = 3 `
`a^2 /(abc)+ b^2/(abc) +c^2 /(abc ) = 3`
Hence the value of `a^2 /(bc)+ b^2/(ac) +c^2 /(ab ) = 3`.
APPEARS IN
संबंधित प्रश्न
Without actually calculating the cubes, find the value of the following:
(–12)3 + (7)3 + (5)3
Evaluate the following using identities:
(1.5x2 − 0.3y2) (1.5x2 + 0.3y2)
Find the cube of the following binomials expression :
\[\frac{1}{x} + \frac{y}{3}\]
If a + b = 10 and ab = 21, find the value of a3 + b3
If a + b + c = 9 and a2+ b2 + c2 =35, find the value of a3 + b3 + c3 −3abc
If a + b + c = 0, then write the value of \[\frac{a^2}{bc} + \frac{b^2}{ca} + \frac{c^2}{ab}\]
If \[x + \frac{1}{x} = 3\] then \[x^6 + \frac{1}{x^6}\] =
75 × 75 + 2 × 75 × 25 + 25 × 25 is equal to
If a - b = 0.9 and ab = 0.36; find:
(i) a + b
(ii) a2 - b2.
If 3x + 4y = 16 and xy = 4, find the value of 9x2 + 16y2.
If a2 - 5a - 1 = 0 and a ≠ 0 ; find:
- `a - 1/a`
- `a + 1/a`
- `a^2 - 1/a^2`
Use the direct method to evaluate :
(3b−1) (3b+1)
Expand the following:
(x - 5) (x - 4)
Expand the following:
(3x + 4) (2x - 1)
Expand the following:
`(2"a" + 1/(2"a"))^2`
If `"a" + 1/"a" = 6;`find `"a" - 1/"a"`
If `"a" - 1/"a" = 10`; find `"a"^2 - 1/"a"^2`
If p2 + q2 + r2 = 82 and pq + qr + pr = 18; find p + q + r.
Simplify:
(3a + 2b - c)(9a2 + 4b2 + c2 - 6ab + 2bc +3ca)
Simplify:
(2x - 4y + 7)(2x + 4y + 7)
