Is 13,12,19 a pythagorean triple? why?

For the equation below, x is the input and y is the output. y = -4x + 3 if the input is -8, then the output is

Lindsay used two points, (x,y; ) and (+2.82), to find the equation of the line, y = mx + b, that passes through the points. y2-y, first, she used the definition of slope and determined that the value of mis x, - . given this information, which expression must represent the value of b?

Find the cosine function that is represented in the graph.