Ask your own question, for FREE!
Mathematics 12 Online
OpenStudy (anonymous):

what are the zeros of h(x)=2x^2-16x+27

OpenStudy (anonymous):

As it's a quadratic equation you can simply use this formula: \[ x_{1,2} = \frac{1}{2a}\left[-b\pm \sqrt{b^2-4ac}\right] \]

OpenStudy (anonymous):

Do you know it?

OpenStudy (anonymous):

to find the possible zeros?

OpenStudy (anonymous):

yes

OpenStudy (anonymous):

it's basically the standard formula

OpenStudy (anonymous):

but i think there is more then 1 zero

OpenStudy (anonymous):

okay let me show you

OpenStudy (anonymous):

thank you because i dont understand

OpenStudy (anonymous):

??

OpenStudy (anonymous):

\[h(x) = \underbrace{2}_{a}x^2-\underbrace{16}_{b}x+\underbrace{27}_c\] Now we plug that into the formula:\[ x_{1/2} = \frac{1}{4}\left[ -(-16) \pm \sqrt{16^2 - 4\cdot2\cdot27}\right] \] \[ = \frac{1}{4}\left[ 16 \pm \sqrt{256 - 216}\right] \] \[ = \frac{1}{4}\left[ 16 \pm \sqrt{40}\right] \] \[ = \frac{1}{2}\left[ 8 \pm 2\sqrt{10}\right] \] Now we can get the zeros as:\[ x_1 = \frac{1}{2}\left[ 8 + 2\sqrt{10}\right], \quad x_2 = \frac{1}{2}\left[ 8 - 2\sqrt{10}\right] \]

OpenStudy (anonymous):

i got the same answer, thanks so much

OpenStudy (anonymous):

You're right that there are two solutions, they exists because we take the squareroot of something. Which means there are necessarily two solutions, because the result of that squareroot can either be negative or positive. \[ \sqrt{-a^2} = \sqrt{-a(-a)} = \sqrt{a^2} = a \] So we cannot tell whether which means we cannot tell whether a was positive or negative int the beginning.

OpenStudy (anonymous):

You're welcome

OpenStudy (anonymous):

how do i find the y- intercept of f(x)= (x^2-6x-7)/(4x^2-36x+56)

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Latest Questions
Arriyanalol: i need help
1 day ago 7 Replies 1 Medal
Arriyanalol: CONGRATS to me
1 day ago 8 Replies 2 Medals
Legomaster346: What colleges are good that are near Arab Alabama?
1 week ago 5 Replies 0 Medals
Arriyanalol: i need help
1 week ago 6 Replies 2 Medals
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!