F (x) = x^2+3 find and simplify f (t-5)

And f (a+h) - f (a), f (a) - f (a-h)

1. (t-5) ^2+3=t^2-10t+12+3=t^2-10t+15.

2. (a+h) ^2+3=a^2+2ah+h^2+3

(a^2) + 3=a^2+3. Subtracting, we get h^2+2ah.

3. (a^2) + 3=a^2+3

(a-h) ^2+3=a^2-2ah+h^2+3. Subtracting, we get 2ah-h^2.