20. if sin 25° =.4226, find sin 155°. 21. i
20. if sin 25° =.4226, find sin 155°. 21. i
Answer
Explanation:
Step1: Use the trigonometric identity
We know that (\sin(180^{\circ}-\alpha)=\sin\alpha). Here, for (\sin155^{\circ}), we can write (155^{\circ}=180^{\circ} - 25^{\circ}). So, (\sin155^{\circ}=\sin(180^{\circ}- 25^{\circ})).
Step2: Apply the identity
By the identity (\sin(180^{\circ}-\alpha)=\sin\alpha), when (\alpha = 25^{\circ}), we have (\sin(180^{\circ}-25^{\circ})=\sin25^{\circ}).
Answer:
(0.4226)