Posted by Shane on .
Using the exact trigonometric ratios of 45 degree,30 degree and 60 degree,evaluate the following,leaving where necessary your answer in surd form. (a) 3 sin 30 degree2 cos 60 degree (b)(tan 45 degree)(4 cos 60 degree2 cos 60 degree)

Maths 
Knights,
sin 30 = 1/2
thus, we get 3/2  2cos 60
cos 60 = 1/2
thus we get 3/2  2/2 = 1/2
tan45 = 1
so the equation is just 4cos60  2cos60
cos 60 = 1/2, as previously mentioned
thus, we get 2  1 = 1.....
btw...I think you can just plug these functions into your calculator to figure these out, it is not too hard.