The sine and the cosine could be for the same angle, but the secant is not the reciprocal of the cosine. The correct answer is: $\displaystyle{\sin{{X}}}=\frac{{3}}{{4}}\usepackage{cmbright}\Huge\$ , $\displaystyle{\cot{{X}}}=\frac{\sqrt{{7}}}{{3}}\usepackage{cmbright}\Huge\$ , $\displaystyle{\tan{{X}}}=\frac{{3}}{\sqrt{{7}}}\usepackage{cmbright}\Huge\$