Advertisements
Advertisements
प्रश्न
Evaluate the following using identities:
`(2x+ 1/x)^2`
Advertisements
उत्तर
In the given problem, we have to evaluate expressions by using identities.
Given `[2x - 1/x]^2`
We shall use the identity `(a - b)^2 = a^2 - 2ab + b^2`
Here a = 2x
`b = 1/x`
By applying identity we get
`[2x - 1/x]^2 = (2x)^2 + (1/x)^2 - 2 xx 2 xx x xx 1/x`
`= (2x xx 2x) + (1/x xx 1/x) - 2 xx 2 xx x xx 1/x`
` = 4x^2 + 1/x^2 - 4`
Hence the value of `[2x - 1/x]^2 is [4x^2 + 1/x^2 - 4]`
APPEARS IN
संबंधित प्रश्न
Expand the following, using suitable identity:
(x + 2y + 4z)2
Factorise the following:
27 – 125a3 – 135a + 225a2
What are the possible expressions for the dimensions of the cuboids whose volume is given below?
| Volume : 12ky2 + 8ky – 20k |
Find the cube of the following binomials expression :
\[2x + \frac{3}{x}\]
Evaluate of the following:
1113 − 893
Find the following product:
(7p4 + q) (49p8 − 7p4q + q2)
If a + b = 6 and ab = 20, find the value of a3 − b3
If \[x + \frac{1}{x}\] 4, then \[x^4 + \frac{1}{x^4} =\]
Expand the following:
(3x + 4) (2x - 1)
Expand the following:
(2x - 5) (2x + 5) (2x- 3)
Expand the following:
(x - 3y - 2z)2
Which one of the following is a polynomial?
The coefficient of x in the expansion of (x + 3)3 is ______.
If `49x^2 - b = (7x + 1/2)(7x - 1/2)`, then the value of b is ______.
Expand the following:
(3a – 5b – c)2
Factorise the following:
16x2 + 4y2 + 9z2 – 16xy – 12yz + 24xz
Find the following product:
`(x/2 + 2y)(x^2/4 - xy + 4y^2)`
