Advertisements
Advertisements
Question
Show that (m – n)2 + (m + n)2 = 2(m2 + n2)
Sum
Advertisements
Solution
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)
shaalaa.com
Is there an error in this question or solution?
APPEARS IN
RELATED QUESTIONS
Expand (5p – 1)2
(a – 1)2 = a2 – 1
The factors of x2 – 6x + 9 are
Simplify: (a + b)2 – (a – b)2
A square lawn has a 2 m wide path surrounding it. If the area of the path is 136 m2, find the area of lawn
Factorised form of 4y2 – 12y + 9 is ______.
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
a2y3 – 2aby2 + b2y
Factorise the following.
y2 + 4y – 21
Factorise the following.
y2 – 2y – 15
Factorise the following.
x2 + 4x – 77
