Advertisements
Advertisements
प्रश्न
Show that (m – n)2 + (m + n)2 = 2(m2 + n2)
Advertisements
उत्तर
Taking the L.H.S = (m – n)2 + (m + n)2
= m2 – 2mn + n2 + m2 + 2mn + n2
= m2 + n2 + m2 + n2
= 2m2 + 2n2 ...`[∵ {:(("a" + "b")^2 - 4"ab" = "a"^2 + 2"ab" + "b"^2),(("a" - "b")^2 = "a"^2 - 2"ab" + "b"^2)]`
= 2(m2 + n2)
= R.H.S
∴ (m – n)2 + (m + n)2 = 2(m2 + n2)
APPEARS IN
संबंधित प्रश्न
Expand: (98)2
Factors of 4 – m2 are
Expand the following square, using suitable identities
(b – 7)2
Expand the following square, using suitable identities
(xyz – 1)2
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
p2y2 – 2py + 1
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
9x2 – 12x + 4
Factorise the following.
x2 – 10x + 21
If x – y = 13 and xy = 28, then find x2 + y2.
Verify the following:
(a – b)(a – b)(a – b) = a3 – 3a2b + 3ab2 – b3
Subtract b(b2 + b – 7) + 5 from 3b2 – 8 and find the value of expression obtained for b = – 3.
