please help

[christina18]

1. If f(x)=x^2, find f(8-square root 5).

f(x) = x^2 then f(2) = 2^2 = 4, f(9) = 9^2 = 81.

So, f(8- sqr(5)) = (8 - sqr(5))^2 = ?.

a. 89-16sqr(5)
b. 64-2sqr(5)
c. 8-2sqr(5)
d. 69-16sqr(5)

*Is the correct choice D?


2. Determine the type of number that the solutions of x^2-2x+5=0 will be:
a. one real
b. two real
c. two non real
d. no solution
*choice D

 

[happy]

Show your reasoning for each.

 

[Denis]

1: D is correct; why were you unsure?

2: D is incorrect; try solving equation using quadratic formula.

 

[christina18]

Determine the type of number that the solutions of x^2-2x+5=0 will be:
a. one real
b. two real
c. two non real
d. no solution

ax^2 + bx + c = 0

Is the correct choice B?

 

[pka]

Determine the type of number that the solutions of x^2-2x+5=0 will be:
a. one real b. two real c. two non real d. no solution
ax^2 + bx + c = 0
Is the correct choice B? No it is not.

\(\displaystyle b^2 - 4ac < 0\).
What does that tell us?

 

[christina18]

It tells us that there is two non-real?

 

[stapel]

It tells us that there is two non-real?

If the above means "the inequality tells us that the quadratic has two non-real solutions", then yes.

Eliz.