Advertisements
Advertisements
Question
If a2 + b2 = 29 and ab = 10, find : a + b
Sum
Advertisements
Solution
(a + b)2 = a2 + b2 + 2ab
⇒ (a + b)2 = 29 + 2×10
⇒ (a + b)2 = 29 + 20
⇒ (a + b)2 = 49
⇒ a + b = `sqrt49`
⇒ a + b = ±7
shaalaa.com
Application of Formulae
Is there an error in this question or solution?
APPEARS IN
RELATED QUESTIONS
If a – b = 6 and ab = 16, find a2 + b2
If a2 + b2 = 29 and ab = 10, find : a − b
If `"a"^2+ 1/"a"^2=23`, find : `"a" +1/"a"`
Find : a + b + c, if a2 + b2 + c2 = 83 and ab + bc + ca = 71.
Find:
`a^3-1/a^3`, if `a -1/a = 4`.
If `2"x"-1/(2"x")=4`, find : `4"x"^2+1/(4"x"^2)`
If `3"x"+1/(3"x")=3`, find : `27"x"^3+1/(27"x"^3)`
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 = 8 and ab = 15, find a3 + b3.
If 5x – 4y = 7 and xy = 8, find : 125x3 – 64y3.
