If f(x) = 4x^2 - x+1, then f(a+1) equals
We are just substituting (a + 1) for x.....so we have
4(a + 1)^2 - (a + 1) + 1 simplify
4 ( a^2 + 2a + 1) - a - 1 + 1
4a^2 + 8a + 4 - a - 1 + 1
4a^2 + 7a + 4