Help please
Find f(2) and f(a+h) when f(x)=3x^2+2x+4
by the time you get to pre-calc, you surely know how to evaluate a function for a specific value. Just plug it in!
f(2) = 3*2^2 + 2*2 + 4
f(a+h) = 3(a+h)^2 + 2(a+h) + 4
and you can expand that if you wish
f(x) = 3x^2 + 2x + 4
whatever replaces x, replace it in the algebraic expression
f(♠) = 3♠^2 + 2♠ + 4
f(☂) = 3☂^2 + 2☂ + 4
f(2) = 3(2)^2 + 2(2) + 4 = 20
follow the same pattern:
f(a+h) = 3(a+h)^2 + 2(a+h) + 4
= 3(a^2 + 2ah + h^2) + 2a + 2h + 4
= 3a^2 + 6ah + 3h^2 + 2a + 2h + 4
= 3a^2 + 8ah + 3h^2 + 2h + 4
Thank you guys so much.
To find the value of f(2), substitute 2 into the equation for f(x) and evaluate the expression:
f(x) = 3x^2 + 2x + 4
Replace x with 2:
f(2) = 3(2)^2 + 2(2) + 4
= 3(4) + 4 + 4
= 12 + 4 + 4
= 20
So, f(2) = 20.
To find the value of f(a+h), we substitute a+h into the equation for f(x):
f(x) = 3x^2 + 2x + 4
Replace x with (a+h):
f(a+h) = 3(a+h)^2 + 2(a+h) + 4
Simplify the expression:
f(a+h) = 3(a^2 + 2ah + h^2) + 2(a+h) + 4
= 3a^2 + 6ah + 3h^2 + 2a + 2h + 4
So, f(a+h) = 3a^2 + 6ah + 3h^2 + 2a + 2h + 4.