Advertisements
Advertisements
प्रश्न
If a2 + b2 + c2 = 41 and a + b + c = 9; find ab + bc + ca.
योग
Advertisements
उत्तर
(a + b + c)2 = (9)2
a2 + b2 + c2 + 2ab + 2bc + 2ca = 81
⇒ 41 + 2(ab + bc + ca) = 81
⇒ 2(ab + bc + ca)
= 81 - 41
= 40
⇒ ab + bc + ca
= 20.
shaalaa.com
क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
APPEARS IN
संबंधित प्रश्न
Factorise the following:
`27p^3-1/216-9/2p^2+1/4p`
if `x^2 + 1/x^2 = 79` Find the value of `x + 1/x`
If a + b = 10 and ab = 21, find the value of a3 + b3
If \[x - \frac{1}{x} = \frac{1}{2}\],then write the value of \[4 x^2 + \frac{4}{x^2}\]
If \[x^3 + \frac{1}{x^3} = 110\], then \[x + \frac{1}{x} =\]
If a1/3 + b1/3 + c1/3 = 0, then
Evaluate: (2a + 0.5) (7a − 0.3)
Expand the following:
(m + 8) (m - 7)
If `"a" - 1/"a" = 10`; find `"a"^2 - 1/"a"^2`
If a + b + c = 9 and ab + bc + ca = 26, find a2 + b2 + c2.
