A counterexample for the expression sin y tan y= cos y is 0.

Answer:TrueStep-by-step explanation:To answer this question we must evaluatey = 0° on both sides of the equation.For the left side we have:[tex]sin(0\°) tan(0\°)[/tex]We know that [tex]tan(0\°) =\frac{sin(0\°)}{cos(0\°)}[/tex]We know that [tex]cos(0\°) = 1[/tex] and [tex]sin(0\°) = 0[/tex].Therefore [tex]tan(0\°) = 0[/tex].Then the left-hand side of the equals is equal to zero.On the right side we have:[tex]cos(y)[/tex]When evaluating [tex]cos(y)[/tex] at [tex]y = 0[/tex]We have to [tex]cos(0\°) = 1[/tex].0 ≠ 1The equation is not satisfied. Therefore y = 0 ° is a counterexample to the equation