Advertisements
Advertisements
प्रश्न
Find : a + b + c, if a2 + b2 + c2 = 83 and ab + bc + ca = 71.
Advertisements
उत्तर
(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca
⇒ (a + b + c)2 = 83 + 2(ab + bc + ca)
⇒ (a + b+ c)2 = 83 + 2×71
⇒ (a + b + c)2 = 83 + 142
⇒ (a + b + c)2 = 225
⇒ a + b + c = `sqrt225`
⇒ a + b +c = ±15
APPEARS IN
संबंधित प्रश्न
If a2 + b2 = 29 and ab = 10, find : a + b
If a2 + b2= 10 and ab = 3; find : a + b
If `"a" - 1/"a"=4`, find : `"a"^2+1/"a"^2`
If `"a"^2+ 1/"a"^2=11`, find : `"a" -1/"a"`
Find:
`a^3-1/a^3`, if `a -1/a = 4`.
If `3"x"+1/(3"x")=3`, find : `9"x"^2+1/(9"x"^2)`
The sum of the squares of two numbers is 13 and their product is 6. Find:
(i) the sum of the two numbers.
(ii) the difference between them.
If a + b + c = 11 and a2 + b2 + c2 = 81, find : ab + bc + ca.
If 3x + 2y = 9 and xy = 3, find : 27x3 + 8y3.
The difference between the two numbers is 5 and their products are 14. Find the difference between their cubes.
