For the linear equation y=-10+5x the x intercept is ?

Which equation represents the function on the graph?

Askyscraper is 396 meters tall. at a certain time of day, it casts a shadow that is 332 meters long.at what angle is the sun above the horizon at that time?

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).