4 cos²x – 1=0

What is the solution?

or

Step-by-step explanation:

So, when cos(x) is equal to

   ?

For

We are talking about x = 60º and x = 300º, Quadrant I and IV, respectively. In radians:

or

For

We are talking about x = 120º and x = 240º, Quadrant II and III, respectively. In radians:

or

y = 1/2x - 4

Step-by-step explanation:

The x-intercept is when y = 0, so it would be:

-x  + 2 * 0 = 4

-x = 4

x = -4

That means the x-intercept is (0, -4)

The parallel line would have the same slope as this one, so:

The parallel line has a slope of 1/2

So now you need to find the equation of a line that has a slope of 1/2 and passes through the point (0, -4)

Put it in point slope form:

y - (-4) = 1/2(x - 0)

y + 4 = 1/2x

y = 1/2x - 4