Equation

[rachelmaddie]

Hi, can someone please check my work for this equation?

We have the functions f(x) = 3x^2 - 2 and g(x) = 4x + 2 and we must find the value of (f + g)(2)
Known: (f+ g)2 = f(2) + g(2)

Substitute 2 in the place of x for f(x) and g(x).
—> 3(2)^2 - 2 + 4(2) + 2
—> 3(4) - 2 + 8 + 2
—> 12 - 2 + 8 + 2 = 20
Therefore, (f + g)2 = 20

 

[yoscar04]

It looks fine.

 

[Dr.Peterson]

You should write (f + g)(2), not (f + g)2, though some authors might accept the latter.

Another way you could do this is to separately evaluate f(2) = 10 and g(2) = 10, then add them. Either way is equally good.

 

[rachelmaddie]

You should write (f + g)(2), not (f + g)2, though some authors might accept the latter.

Another way you could do this is to separately evaluate f(2) = 10 and g(2) = 10, then add them. Either way is equally good.

Okay, got it!