# Example 12 - Chapter 9 Class 8 Algebraic Expressions and Identities

Last updated at Dec. 24, 2018 by Teachoo

Last updated at Dec. 24, 2018 by Teachoo

Transcript

Example 12 Using Identity (II), find (i) (4πβ3π)^2 (4πβ3π)^2 (πβπ)^2=π^2+π^2β2ππ Putting π = 4π & π = 3π = (4π)^2+(3π)^2β2(4π)(3π) = (4^2Γπ^2 )+(3^2Γπ^2 )β(2Γ4Γ3)Γ(πΓπ) = πππ^π+ππ^πβππππ Example 12 Using Identity (II), find (ii) (4.9)^2 (4.9)^2 = (5β0.1)^2 (πβπ)^2=π^2+π^2β2ππ Putting π = 5 & π = 0.1 = (5)^2+(0.1)^2β2(5)(0.1) = 25+(1/10)^2β(2Γ5Γ1/10) = 25+1^2/γ10γ^2 β(10/10) = 25+1/100β1 = 24+1/100 = (24 Γ 100 + 1)/100 = (2400 + 1)/100 = 2401/100 = ππ.ππ

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