If f(x + y, x – y) = xy for all x, y ∈ R, then the value of f(5, 1) is
Answer & explanation
Correct answer: option 4
Let x + y = 5 and x – y = 1. Then x = 3 and y = 2
∴ f(5, 1) = f(x + y, x – y) = xy = 3(2) = 6
If f(x + y, x – y) = xy for all x, y ∈ R, then the value of f(5, 1) is
Correct answer: option 4
Let x + y = 5 and x – y = 1. Then x = 3 and y = 2
∴ f(5, 1) = f(x + y, x – y) = xy = 3(2) = 6