What is the value of Tangent (t/2) if Cosine (t) = 4/5 and t is in quadrant IV?

In the xy-plane, if the parabola with equation passes through the point (-1, -1), which of the following must be true?

Sundar used linear combination to solve the system of equations shown. he did so by multiplying the first equation by 5 and the second equation by another number to eliminate the y-terms. what number did sundar multiply the second equation by? 2x+9y=41 3x+5y=36

On average, a continental shelf drops 0.12 m per 100 m. at 22.5 m from the shoreline, how much distance has the continental shelf dropped?