Advertisements
Advertisements
प्रश्न
Simplify: (a + b)2 – (a – b)2
Advertisements
उत्तर
Applying the identities
(a + b)2 = a2 + 2ab + b2
(a – b)2 = a2 – 2ab + b2
(a + b)2 – (a – b)2 = a2 + 2ab + b2 – [a2 – 2ab + b2]
= a2 + 2ab + b2 – a2 + 2ab – b2
= a2(1 – 1) + ab(2 + 2) + b2(1 – 1)
= 0a2 + 4ab + 0b2 = 4ab
(a + b)2 – (a – b)2 = 4ab
APPEARS IN
संबंधित प्रश्न
Expand: (98)2
(a – 1)2 = a2 – 1
Evaluate the following, using suitable identity
472
Show that (m – n)2 + (m + n)2 = 2(m2 + n2)
Factorise the following using suitable identity
x2 – 8x + 16
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
x2 – 10x + 25
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
`x^2/4 - 2x + 4`
Factorise the following.
x2 – 10x + 21
If m – n = 16 and m2 + n2 = 400, then find mn.
Verify the following:
(a – b)(a – b)(a – b) = a3 – 3a2b + 3ab2 – b3
