Use the quadratic formula to find the zeros of the function. Round to tenths if necessary. y = 17x2 - 21

Question

campbell_st · Answer

in this question you have a = 17, b = 0 and c = -21

the formula is 

$$x=\frac{-b \pm \sqrt{b^4 - 4ac}}{2a}$$

substitute the values and then evaluate to find the zeros

anonymous · Answer

I have tried and always  get the wrong answer

anonymous · Answer

what did you get?

anonymous · Answer

1.6 Not sure what im  doing wrong

campbell_st · Answer

after substituting you should get 

$$x =\frac{ 0 \pm \sqrt{0^2 - 4\times17\times-21}}{2\times17}$$

this simplifies to 

$$x =\frac{ \pm \sqrt{1428}}{34}$$

which can be simplifed

anonymous · Answer

btw, that should be a b^2 in that radical in your first post...

campbell_st · Answer

oops... ty

anonymous · Answer

didn't matter here anyway... :)

anonymous · Answer

would it be 1.1?

campbell_st · Answer

yes.... thats the approximation

anonymous · Answer

Awesome!