excuse my descripts, hope it will help

(i)to draw the graph, plot all the x intercepts- when 2x=2npi where x is any interger ie ...-3, -2, -1, 0, 1, 2.... and all the maximum, miminium values ie value of 2 when 2x= 2npi -pi where n is any integer and min value -2 when x= 2npi + pi where n is any integer, then join all points

(ii) to find the exact value of **sin(A - B)** find

sine A with (cos A)^2 + (sin A) ^2 = 1 and **cos A = 24/25**

sine B with 1 + (cot B)^2 = (cosec B)^2 and **tan B = 15/8**

cosine B with 1 + (tan B)^2 = (sec B)^2 and **tan B = 15/8**

**** cot B= 1/tanB **and **cosec B = 1/sinB **and** sec B = 1/cos B**

then use formula

sin(A-B) = sin A cosB -cos A sin B

(iii)tan 2x = sin 2x/ cos 2x

= 2sin x cos x / [(cos x)^2 - (sin x)^2]

divide the denominator and numerator by (cos x)^2 and u will get there