Analyze the functions with domain/range and key points.

see below

Step-by-step explanation:   5 19 16 09

cos Θ  =  Adj side / hypotenuse

first we need to calculate the hypotenuse

a² + b² = c²        leg1² + leg2² = hypotenuse²

                           6²     + √7²  = hypotenuse²

                           36     +   7   = hypotenuse²

                               √43    = hypotenuse

cos K  =  Adj side / hypotenuse

cos K =     6 / √43

cos K =     (6 √43) / ((√43)(√43))

cos K =     6√43 / 43

check

or tan Θ =    opp /adj

     K  = inv tan (√7/6)

     Θ  = 23.795°

cos (23.795°) = 0.91499          6√43 / 43 = 0.91499