How do you know what is a non-linear function

Find the value of tan theta if sin theta = 12/13 and theta is in quadrant 2

Acontainer holds 0.7 liters of oil and vinegar. 3/4 of the mixture is vinegar. how many liters of oil are in the container? express your answer as both a fraction and a decimal.

Which statement is true about the local minimum of the graphed function? over the interval[-4,-2], the local minimum is 0. over the interval [-2,-1] , the local minimum is 25. over the interval [-1,4], the local minimum is 0. over the interval [4,7], the local minimum is -7