tan20 - cos70/cos20 thank you so much i am desperate
Follow Math Help Forum on Facebook and Google+
Originally Posted by desperate_on_sunday_night tan20 - cos70/cos20 thank you so much i am desperate Just plug it into your calculator. (Make sure you have it set to degrees and not radians, for the record, I get zero)
Originally Posted by desperate_on_sunday_night tan20 - cos70/cos20 thank you so much i am desperate Or use the fact that $\displaystyle \sin 20 = \sin (90 - 70) = \cos 70$ So $\displaystyle \tan20 - \frac{\cos 70}{\cos 20} = \frac{\sin 20}{\cos 20} - \frac{\cos 70}{\cos 20} = \frac{\cos 70}{\cos 20} - \frac{\cos 70}{\cos 20} = 0$
View Tag Cloud