Question

Need help with 2 questions please work through them with me i dont get any of this ): and i need to finish please (attached pictures)

Answer 1

Hi there! Finding x and y intercepts is pretty easy. To find x, substitute 0 for y. To find y, substitute 0 for x. Do you need to me to explain it further? :)

Answer 2

to find the x-intercepts, you need to find where f(x)=0.

Answer 3

i have already been told this by my teachers including and i guess im just so dumb with math i dont get it ):

Answer 4

Aw don't say that! Let's solve this together.

Let's try to find y first.

Substitute 0 for all of the x's.
\[f(x)=-16(0)^2+22(0)+3\]

\[f(x)=3\]
So, y is 3

Answer 5

wait how did u get the 3?

Answer 6

16*0=0
22*0=0

So, 0+3=3

Answer 7

ohhh okay

Answer 8

so setting x = 0, as mossyfish showed, will give you the y-intercept

and setting y = 0, will give you the x-intercept

Answer 9

have you done quadratic factoring yet?

Answer 10

yes i have but i dont really understand factoring at all and okay thanks and i know how to get part b but what about part C?

Answer 11

ok so \(\bf f(x)=-16x^2+22x+3\implies 0=-16x^2+22x+3
\\ \quad \\
\begin{array}{cccllll}
0=&-16x^2&+22x&+3\\
&{\color{red}{ -8x\cdot 2x}}&
({\color{red}{ -8x}}\cdot {\color{blue}{ 3}})+({\color{red}{ 2x}}\cdot {\color{blue}{ 1}})
&{\color{blue}{ 1\cdot 3}}
\end{array}\implies 0=({\color{red}{ -8x}}+{\color{blue}{ 1}})({\color{red}{ 2x}}+{\color{blue}{ 3}})
\\ \quad \\ \quad \\
\implies
\begin{cases}
0=-8x+1\implies 8x=1\implies x=\frac{1}{8}
\\ \quad \\
\bf 0=2x+3\implies -3=2x\implies -\frac{3}{2}=x
\end{cases}\)

Answer 12

see how the middle term in \(\bf 0=-16x^2+22x+3\) is obtained from the factors of the 1st and last term?

Answer 13

yeah