Find the exact value of the trigonometric expression given t

Find the exact value of the trigonometric expression given that sin u = 8 /17 and cos v = 3/ 5 . (Both u and v are in Quadrant II.) sec(v u)

sin u = 8 /17 and cos v = 3/ 5

cosu = - 15/17 ; sinv = 4/5

sec(v -u) = 1/cos(v -u)

cos(v -u) = cosvcosu +sinvsinu

=(-3/5)(-15/17) + (4/5)(8/17)

= ( 45 +32)/85

= 77/85

So, sec( v -u) = 85/77