sin217.5°+sin272.5° is equal to
cos290°
tan245°
cos230°
sin245°
Explanation for the correct answer:
Simplifying the given expression:
⇒sin217.5°+sin272.5°⇒sin17.5°+sin2(90°–17.5°)∵sin2(90-x)=cos2x⇒sin217.5°+cos217.5°⇒1∵tan45°=1⇒tan45°⇒tan245°∵tan45°=tan245°=1
Therefore, the correct answer is option (B).
Find answers to the following. Write and indicate how you solved them.(i) Is 59 equal to45?(ii) Is 916 equal to 59?(iii) Is 45 equal to 1620?(iv) Is 115 equal to 430?