What basic trigonometric identity would you use to verify that sin x cos x tan x =1 - cos^2 x

We let y equal to the elevation above sea level so that the elevation of the rock climber after x minutes of climbing would be:

y = 2x + 50

His initial height can be calculated when x is equal to zero it is when the climber is not yet climbing. Therefore, the rock climber'sinitial height above sea level would be 50 meters.