Question

The equation $\cos t=\frac{2}{5},\sin t=\frac{3}{5}$ have

• A. unique solution
• B. finitely many solutions
• C. infinitely many solutions
• D. no solution

Answer 1

Answer: (D)

${\cos }^{2}t+{\sin }^{2}t=\frac{13}{25}\ne 1$