How do you find the vertex and intercepts for $f (x) = 9 x^{2} + 7 x + 5$ $f(x)=9x^2+7x+5$ ?

Question

How do you find the vertex and intercepts for $f (x) = 9 x^{2} + 7 x + 5$ $f(x)=9x^2+7x+5$ ?

1 Answer

Impact of this question

1843 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-01-03T21:41:30

vertex = ( $- \frac{7}{18}, \frac{95}{36})$ $-7/18 , 95/36 )$
there are no intercepts with the x-axis

Explanation:

x- coordinate of vertex = $- \frac{b}{2 a}$ $-b/(2a$

compare $9 x^{2} + 7 x + 5 w i t h$ $9x^2 + 7x +5 with$ ax^2 + bx + c #
here a= 9 , b = 7 and c =5

so x-coord = $- \frac{7}{18}$ $- 7/18$

now evaluate $f (- \frac{7}{18})$ $f(-7/18)$

$= 9 {(- \frac{7}{18})}^{2} + 7 (- \frac{7}{18}) + 5$ $= 9(-7/18)^2 + 7 (-7/18) + 5$
$= \frac{49}{36} - (\frac{49}{18}) + 5$ $= 49/36 - (49/18) + 5$
$= \frac{95}{36}$ $= 95/36$

now check discriminant $\nabla$ $grad$ for type of roots

$\nabla = b^{2} - 4 a c$ $grad = b^2 - 4ac$
# = 7^2 -(4 • 9 • 5 )
=49 - 180
= - 131
since discriminant < 0 there are no intercepts

Science

Math

Humanities

... and beyond

How do you find the vertex and intercepts for $f (x) = 9 x^{2} + 7 x + 5$ $f(x)=9x^2+7x+5$ ?

1 Answer

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

How do you find the vertex and intercepts for f(x)=9x2+7x+5f(x)=9x^2+7x+5?

1 Answer

Explanation:

Related questions

Impact of this question

How do you find the vertex and intercepts for $f (x) = 9 x^{2} + 7 x + 5$ $f(x)=9x^2+7x+5$ ?