What whole-number value of k makes the following equation true? cos(16x) cos(8x) + sin(16x) sin(8x) =1 -2sin?(kx) (Record your answer in the numerical-response section below.) Your answer: What is the solution to the equation 5secx -4 =7 in the domain 7 _ _ 27? Round your answer to the nearest hundredth. (Record your answer in the numerical-response section below.) Your answer: The expression tan48 -tango 1 + tan48' tango Is equivalent to tan where 0