Advertisements
Advertisements
प्रश्न
If `"a" + 1/"a"=3`, find `"a"^2+1/"a"^2`
बेरीज
उत्तर
`("a"+1/"a")^2="a"^2+1/"a"^2+2`
`⇒(3)^2="a"^2+1/"a"^2+2`
`⇒9="a"^2+1/"a"^2+2`
`⇒9-2="a"^2+1/"a"^2`
`⇒7="a"^2+1/"a"^2`
`∴"a"^2+1/"a"^2=7`
Alternative Method :
`"a" +1/"a"=3`
`⇒("a"+1/"a")^2=(3)^2`
`⇒"a"^2+1/"a"^2+2=9`
`⇒"a"^2+1/"a"^2=9-2`
`⇒"a"^2+1/"a"^2=7`
shaalaa.com
Application of Formulae
या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
APPEARS IN
संबंधित प्रश्न
If a+b=5 and ab = 6, find a2 + b2
If a2 + b2 = 29 and ab = 10, find : a + b
If a + b + c = 10 and a2 + b2 + c2 = 38, find : ab + bc + ca
If a + b = 6 and ab=8, find : a3 + b3.
If `2"x"-1/(2"x")=4`, find : `4"x"^2+1/(4"x"^2)`
If `2"x"-1/(2"x")=4`, find : `8"x"^3-1/(8"x"^3)`
If `3"x"+1/(3"x")=3`, find : `27"x"^3+1/(27"x"^3)`
If a2 + b2 = 41 and ab = 4, find : a – b
If 3x + 2y = 9 and xy = 3, find : 27x3 + 8y3.
If 5x – 4y = 7 and xy = 8, find : 125x3 – 64y3.
