2 = r cos( – 90°) y ?

To solve this equation, you need to use the definition of cosine and the properties of the unit circle. The definition of cosine states that it is the ratio of the adjacent side to the hypotenuse of a right triangle.

In this case, we have -90 degrees as the angle in cosine function, which means we need to find the value of cos(-90°) in order to solve the equation.

To find cos(-90°), we need to refer to the unit circle. The unit circle is a circle with a radius of 1 unit and is centered at the origin of a coordinate plane.

Since -90° is in the 4th quadrant of the unit circle, we know that the x-coordinate is positive and the y-coordinate is negative.

In the 4th quadrant, the x-coordinate is the cosine value, and the y-coordinate is the sine value. Since the cosine value is positive and the y-coordinate is negative, we can determine that cos(-90°) equals 0 and sin(-90°) equals -1.

So, r cos(-90°) equals r * 0, which is 0. This means that the equation simplifies to 2 = 0 * y, or simply 2 = 0.

Therefore, there is no value of y that satisfies this equation.