Let f(x)= square root of x-3 and g(x)=x^2+5.

(f+g)(-3). Thanks for the help :)

Question

Let f(x)= square root of x-3 and g(x)=x^2+5.

(f+g)(-3).  Thanks for the help :)

jim_thompson5910 · Answer

plug in x = -3 into each function

then evaluate

finally, add up the two results

anonymous · Answer

I got  (square root of 6+ 14)

jim_thompson5910 · Answer

is the function f(x) this

$$\large f(x) = \sqrt{x-3}$$

OR

is it this

$$\large f(x) = \sqrt{x}-3$$

anonymous · Answer

the top one

jim_thompson5910 · Answer

$$\large f(x) = \sqrt{x-3}$$

$$\large f(-3) = \sqrt{-3-3}$$

$$\large f(-3) = \sqrt{-6}$$

jim_thompson5910 · Answer

at this point, have you learned about complex or imaginary numbers?

anonymous · Answer

Yeah I got that

anonymous · Answer

Yes I have

jim_thompson5910 · Answer

ok so 

$$\large f(x) = \sqrt{x-3}$$ 

$$\large f(-3) = \sqrt{-3-3}$$ 

$$\large f(-3) = \sqrt{-6}$$

$$\large f(-3) = i*\sqrt{6}$$

jim_thompson5910 · Answer

g(-3)=(-3)^2 + 5 = 9+5 = 14

g(-3) = 14

---------------------------

(f+g)(-3) = f(-3) + g(-3)

$$\large (f+g)(-3) = i\sqrt{6} + 14$$

$$\large (f+g)(-3) = 14 + i\sqrt{6}$$

anonymous · Answer

Thank you

jim_thompson5910 · Answer

yw