Question

HELP ME!!

Answer 1

Answer:

cos2∅= -0.557

tan2∅= --1.49

Step-by-step explanation:

Given:

cos∅=-8/17

By trigonometric ratios:

as cos∅=adjacent/hypotenuse

hypotenuse= 17

adjacent=-8

Now finding perpendicular using Pythagoras theorem:

c2=a2+b2

17^2=(-8)^2+b^2

289-64=b^2

b^2=225

b=±15

b=-15 as ∅ is in third quadrant so both the opposite and adjacent sides be in 3rd quadrant

tan∅=opposite/adjacent

tan∅=-15/-8

sin∅=-15/17

Now finding cos2∅

cos2∅= 1-2sin^2∅

           =1 - 2(-15/17)^2

           =1 -450/289

            = -161/289

           =-0.557

finding tan2∅

tan2∅= 2tan∅/1-tan^2∅

         = 2(-15/-8) / 1-(-15/-8)^2

          = (15/4) / 1-225/64

           =(15/4) / (-161/64)

            = -240/161

             =-1.49 !