Solve y=x^2 -8x-10

Question

Function

Find the vertex

Find the axis of symmetry

Rewrite in vertex form

(4, - 26)

Evaluate

y = x^{2} - 8 x - 10

Find the x -coordinate of the vertex by substituting a= 1 and b= - 8 into x = - \frac{b}{2 a}

x = - \frac{- 8}{2 \times 1}

Solve the equation for x

x = 4

Find the y-coordinate of the vertex by evaluating the function for x = 4

y = 4^{2} - 8 \times 4 - 10

Calculate

More Steps

Evaluate

4^{2} - 8 \times 4 - 10

Multiply the numbers

4^{2} - 32 - 10

Evaluate the power

16 - 32 - 10

Subtract the numbers

- 26

y = - 26

Solution

(4, - 26)

Show Solution

Testing for symmetry

Testing for symmetry about the origin

Testing for symmetry about the x-axis

Testing for symmetry about the y-axis

Not symmetry with respect to the origin

Evaluate

y = x^{2} - 8 x - 10

To test if the graph of y = x^{2} - 8 x - 10 is symmetry with respect to the origin,substitute -x for x and -y for y

- y = (- x)^{2} - 8 (- x) - 10

Simplify

More Steps

Evaluate

(- x)^{2} - 8 (- x) - 10

Multiply the numbers

(- x)^{2} + 8 x - 10

Rewrite the expression

x^{2} + 8 x - 10

- y = x^{2} + 8 x - 10

Change the signs both sides

y = - x^{2} - 8 x + 10

Solution

Not symmetry with respect to the origin

Show Solution

Identify the conic

Find the standard equation of the parabola

Find the vertex of the parabola

Find the focus of the parabola

(x - 4)^{2} = y + 26

Evaluate

y = x^{2} - 8 x - 10

Swap the sides of the equation

x^{2} - 8 x - 10 = y

Move the constant to the right-hand side and change its sign

x^{2} - 8 x = y - (- 10)

If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses

x^{2} - 8 x = y + 10

To complete the square, the same value needs to be added to both sides

x^{2} - 8 x + 16 = y + 10 + 16

Use a^{2} - 2 ab + b^{2} = (a - b)^{2} to factor the expression

(x - 4)^{2} = y + 10 + 16

Solution

(x - 4)^{2} = y + 26

Show Solution

Solve the equation

x = 4 + 26 + y x = 4 - 26 + y

Evaluate

y = x^{2} - 8 x - 10

Swap the sides of the equation

x^{2} - 8 x - 10 = y

Move the expression to the left side

x^{2} - 8 x - 10 - y = 0

Substitute a= 1,b= - 8 and c= - 10 - y into the quadratic formula x = \frac{- b \pm b ^{2} - 4 a c}{2 a}

x = \frac{8 \pm ( - 8 ) ^{2} - 4 ( - 10 - y )}{2}

Simplify the expression

More Steps

Evaluate

(- 8)^{2} - 4 (- 10 - y)

Multiply the terms

More Steps

Evaluate

4 (- 10 - y)

Apply the distributive property

- 4 \times 10 - 4 y

Multiply the numbers

- 40 - 4 y

(- 8)^{2} - (- 40 - 4 y)

Rewrite the expression

8^{2} - (- 40 - 4 y)

If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses

8^{2} + 40 + 4 y

Evaluate the power

64 + 40 + 4 y

Add the numbers

104 + 4 y

x = \frac{8 \pm 104 + 4 y}{2}

Simplify the radical expression

More Steps

Evaluate

104 + 4 y

Factor the expression

4 (26 + y)

The root of a product is equal to the product of the roots of each factor

4 \times 26 + y

Evaluate the root

More Steps

Evaluate

4

Write the number in exponential form with the base of 2

2^{2}

Reduce the index of the radical and exponent with 2

2

2 26 + y

x = \frac{8 \pm 2 26 + y}{2}

Separate the equation into 2 possible cases

x = \frac{8 + 2 26 + y}{2} x = \frac{8 - 2 26 + y}{2}

Simplify the expression

More Steps

Evaluate

x = \frac{8 + 2 26 + y}{2}

Divide the terms

More Steps

Evaluate

\frac{8 + 2 26 + y}{2}

Rewrite the expression

\frac{2 ( 4 + 26 + y )}{2}

Reduce the fraction

4 + 26 + y

x = 4 + 26 + y

x = 4 + 26 + y x = \frac{8 - 2 26 + y}{2}

Solution

More Steps

Evaluate

x = \frac{8 - 2 26 + y}{2}

Divide the terms

More Steps

Evaluate

\frac{8 - 2 26 + y}{2}

Rewrite the expression

\frac{2 ( 4 - 26 + y )}{2}

Reduce the fraction

4 - 26 + y

x = 4 - 26 + y

x = 4 + 26 + y x = 4 - 26 + y

Show Solution

Rewrite the equation

r = \frac{sin ( θ ) + 8 cos ( θ ) - 1 + 103 cos ^{2} ( θ ) + 8 sin ( 2 θ )}{2 cos ^{2} ( θ )} r = \frac{sin ( θ ) + 8 cos ( θ ) + 1 + 103 cos ^{2} ( θ ) + 8 sin ( 2 θ )}{2 cos ^{2} ( θ )}

Evaluate

y = x^{2} - 8 x - 10

Move the expression to the left side

y - x^{2} + 8 x = - 10

To convert the equation to polar coordinates,substitute x for r cos (θ) and y for r sin (θ)

sin (θ) \times r - (cos (θ) \times r)^{2} + 8 cos (θ) \times r = - 10

Factor the expression

- cos^{2} (θ) \times r^{2} + (sin (θ) + 8 cos (θ)) r = - 10

Subtract the terms

- cos^{2} (θ) \times r^{2} + (sin (θ) + 8 cos (θ)) r - (- 10) = - 10 - (- 10)

Evaluate

- cos^{2} (θ) \times r^{2} + (sin (θ) + 8 cos (θ)) r + 10 = 0

Solve using the quadratic formula

r = \frac{- sin ( θ ) - 8 cos ( θ ) \pm ( sin ( θ ) + 8 cos ( θ ) ) ^{2} - 4 ( - cos ^{2} ( θ ) ) \times 10}{- 2 cos ^{2} ( θ )}

Simplify

r = \frac{- sin ( θ ) - 8 cos ( θ ) \pm 1 + 103 cos ^{2} ( θ ) + 8 sin ( 2 θ )}{- 2 cos ^{2} ( θ )}

Separate the equation into 2 possible cases

r = \frac{- sin ( θ ) - 8 cos ( θ ) + 1 + 103 cos ^{2} ( θ ) + 8 sin ( 2 θ )}{- 2 cos ^{2} ( θ )} r = \frac{- sin ( θ ) - 8 cos ( θ ) - 1 + 103 cos ^{2} ( θ ) + 8 sin ( 2 θ )}{- 2 cos ^{2} ( θ )}

Use \frac{- a}{b} = \frac{a}{- b} = - \frac{a}{b} to rewrite the fraction

r = \frac{sin ( θ ) + 8 cos ( θ ) - 1 + 103 cos ^{2} ( θ ) + 8 sin ( 2 θ )}{2 cos ^{2} ( θ )} r = \frac{- sin ( θ ) - 8 cos ( θ ) - 1 + 103 cos ^{2} ( θ ) + 8 sin ( 2 θ )}{- 2 cos ^{2} ( θ )}

Solution

r = \frac{sin ( θ ) + 8 cos ( θ ) - 1 + 103 cos ^{2} ( θ ) + 8 sin ( 2 θ )}{2 cos ^{2} ( θ )} r = \frac{sin ( θ ) + 8 cos ( θ ) + 1 + 103 cos ^{2} ( θ ) + 8 sin ( 2 θ )}{2 cos ^{2} ( θ )}

Show Solution

Function

Testing for symmetry

Identify the conic

Solve the equation

Rewrite the equation

Graph