How do you find the exact value of #sec120#?
1 Answer
Mar 8, 2017
#sec120^@=-2#
Explanation:
Using the
#color(blue)"trigonometric identity"#
#color(red)(bar(ul(|color(white)(2/2)color(black)(sectheta=1/costheta;costheta≠0)color(white)(2/2)|)))#
#rArrsec120^@=1/cos120^@#
#"now "cos120^@=-cos60^@=-1/2#
#rArrsec120^@=1/(-1/2)=-2#
