Find the x and y Intercepts f(x)=x^2+8x+15

$f (x) = x^{2} + 8 x + 15$

Step 1

Find the x-intercepts.

To find the x-intercept(s), substitute in $0$ for $y$ and solve for $x$ .

$0 = x^{2} + 8 x + 15$

Solve the equation.

Rewrite the equation as $x^{2} + 8 x + 15 = 0$ .

$x^{2} + 8 x + 15 = 0$

Factor $x^{2} + 8 x + 15$ using the AC method.

Consider the form $x^{2} + b x + c$ . Find a pair of integers whose product is $c$ and whose sum is $b$ . In this case, whose product is $15$ and whose sum is $8$ .

$3, 5$

Write the factored form using these integers.

$(x + 3) (x + 5) = 0$

If any individual factor on the left side of the equation is equal to $0$ , the entire expression will be equal to $0$ .

$x + 3 = 0$

$x + 5 = 0$

Set $x + 3$ equal to $0$ and solve for $x$ .

Set $x + 3$ equal to $0$ .

$x + 3 = 0$

Subtract $3$ from both sides of the equation.

$x = - 3$

Set $x + 5$ equal to $0$ and solve for $x$ .

Set $x + 5$ equal to $0$ .

$x + 5 = 0$

Subtract $5$ from both sides of the equation.

$x = - 5$

The final solution is all the values that make $(x + 3) (x + 5) = 0$ true.

$x = - 3, - 5$

x-intercept(s) in point form.

x-intercept(s): $(- 3, 0), (- 5, 0)$

Step 2

Find the y-intercepts.

To find the y-intercept(s), substitute in $0$ for $x$ and solve for $y$ .

$y = {(0)}^{2} + 8 (0) + 15$

Solve the equation.

Remove parentheses.

$y = 0^{2} + 8 (0) + 15$

Remove parentheses.

$y = {(0)}^{2} + 8 (0) + 15$

Simplify ${(0)}^{2} + 8 (0) + 15$ .

Simplify each term.

Raising $0$ to any positive power yields $0$ .

$y = 0 + 8 (0) + 15$

Multiply $8$ by $0$ .

$y = 0 + 0 + 15$

Simplify by adding numbers.

Add $0$ and $0$ .

$y = 0 + 15$

Add $0$ and $15$ .

$y = 15$

y-intercept(s) in point form.

y-intercept(s): $(0, 15)$

Step 3

List the intersections.

x-intercept(s): $(- 3, 0), (- 5, 0)$

y-intercept(s): $(0, 15)$

Step 4

Find the x and y Intercepts f(x)=x^2+8x+15

Related Questions

Support LCMGCF.com by disabling your adblocker.