Question

Verify the following identities. (a+b+c)^2 = a^2 + b^2 + c^2 + 2ab + 2bc + 2ca

Answer 1

Answer:

$(a + b + c) {}^{2} \\ = (a + b + c) {}^{2} = (a + b + c)(a + b + c \\ a {}^{2} + ab + ac + ab + b {}^{2} + bc + ac + bc + c {}^{2} \\ = a {}^{2} + b {}^{2} + c {}^{2} + 2ab + 2bc + 2ca \\ (proved)$