Secure https Precalculus 20170104 F Homework 62 63 64 l 6 of

Secure https Precalculus 201701-04 F Homework 6.2, 6.3, 6.4 l 6 of 20 Use the information given below to find cos(a -B). tana-3, with a in quadrant III Sln. with in quadrant I Give the exact answer, not a decimal approximation. cos (u B) Worked Example How to bug c....mp4 for loop png Trig cheat sheet (2) pdf A Na doc. dock a Ask me any Save For Later Richard BB Submit Assignment Sha all x 54 PM 3/1/20

Solution

we have given tan()=4/3 with III rd quadrant and sin()=3/5 with in I quadrant

cos()=sqrt(1-sin²())=sqrt(1-9/25)=sqrt(16/25)=4/5

sec²()-tan²()=1 implies sec²()=1+tan²()=1+16/9=25/9

sec()=5/3,cos()=1/sec() =3/5

sin()=sqrt(1-cos²())=sqrt(1-9/25)=sqrt(16/25)=4/5

cos(-)=coscos+sinsin

=(3/5)*(4/5)+(4/5)*(3/5)

=(12/25)+(12/25)

cos(-)=24/25