Trigonometry 7th Edition

$\sin 23^{\circ}$ = $0.3907$ $\cos 67^{\circ}$ = $0.3907$ Thus, results justify the Cofunction Theorem.
Given pair is- $\sin 23^{\circ}$ , $\cos 67^{\circ}$ Using calculator in degree mode- (23 → $\sin$) and ( 67 → $\cos$) $\sin 23^{\circ}$ = $0.3907311285$ Rounding to four places past the decimal point- $\sin 23^{\circ}$ = $0.3907$ $\cos 67^{\circ}$ = $0.3907311285$ Rounding to four places past the decimal point- $\cos 67^{\circ}$ = $0.3907$ Hence- $\sin 23^{\circ}$ = $\cos 67^{\circ}$ Thus, results justify the Cofunction Theorem.