Advertisements
Advertisements
प्रश्न
If `"a"^2 + (1)/"a"^2 = 14`; find the value of `"a" + (1)/"a"`
बेरीज
Advertisements
उत्तर
Using (a + b)2 = a2 + 2ab + b2
`("a" + 1/"a")^2`
= `"a"^2 + 2"a"(1/"a") + (1/"a")^2`
⇒ `("a" + 1/"a")^2 = "a"^2 + 2 + (1)/"a"^2`
⇒ `("a" + 1/"a")^2 = "a"^2 + (1)/"a"^2 + 2`
⇒ `("a" + 1/"a")^2` = 14 + 2
⇒ `("a" + 1/"a")^2` = 16
⇒ `"a" + (1)/"a"` = ±4.
shaalaa.com
या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
APPEARS IN
संबंधित प्रश्न
Write the following cube in expanded form:
(2x + 1)3
Factorise the following:
27y3 + 125z3
Write in the expanded form:
`(2 + x - 2y)^2`
Simplify (a + b + c)2 + (a - b + c)2 + (a + b - c)2
Evaluate of the following:
463+343
Simplify of the following:
\[\left( \frac{x}{2} + \frac{y}{3} \right)^3 - \left( \frac{x}{2} - \frac{y}{3} \right)^3\]
Find the square of : 3a - 4b
If x + y = `7/2 "and xy" =5/2`; find: x - y and x2 - y2
Evaluate: (9 − y) (7 + y)
Simplify by using formula :
(2x + 3y) (2x - 3y)
