A submarine descends at a rate of 2.6 kilometers per hour. If the ocean floor is 6.24 kilometers below sea level, how long will it take the submarine to descend to the ocean floor?
Round your answer to the nearest tenth.

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b