The y-intercept is the point at which a function cuts the y-axis. It can be found by evaluating the function at x=0. The coordinates of that point will be:
[tex](0,f(0))[/tex]Evaluate f(0):
[tex]\begin{gathered} f(x)=x^2+2x-15 \\ \Rightarrow f(0)=(0)^2+2(0)-15 \\ =0+0-15 \\ =-15 \end{gathered}[/tex]Since f(0) = -15 , then the coordinates of the y-intercept are:
[tex](0,-15)[/tex]