SOLUTION: if cos(x+y)=0.7547 and cos(x-y)=0.9703, then find the value of cos(x)cos(y).

Question 445211: if cos(x+y)=0.7547 and cos(x-y)=0.9703, then find the value of cos(x)cos(y).
Answer by AnlytcPhil(1806) (Show Source): You can put this solution on YOUR website!


 cos(x+y)=0.7547 and cos(x-y)=0.9703

find the value of cos(x)cos(y)

cos(x+y) = cos(x)cos(y) - sin(x)sin(y) = 0.7547
cos(x-y) = cos(x)cos(y) + sin(x)sin(y) = 0.9703  Now add these eqs.:
-----------------------------------------------
          2cos(x)cos(y)                = 1.7250 

           
          2cos(x)cos(y) = 1.7250

Divide both sides by 2:

           cos(x)cos(y) =  .8625
          
Edwin

RELATED QUESTIONS
Suppose sin x = 1/7 cos x > 0, sin y = −2/5 and cos y < 0. Then cos x = cos y (answered by ewatrrr)
Suppose sin x = 1/7 cos x > 0, sin y = −2/5 and cos y < 0. Then cos x = cos y (answered by stanbon)
Suppose sin x = 1/7 cos x > 0, sin y = −2/5 and cos y < 0. Then cos x =... (answered by lwsshak3)
Suppose sin x = 5/7 cos x > 0, sin y = − 1/5 and cos y < 0. Then cos x = cos... (answered by lwsshak3)
Suppose sin x =2/7,cos x > 0, sin y = − 2/5 and cos y < 0. Then cos x= cos y= Find (answered by CPhill)
Verify the identity. (cos(x) - cos(y))/(sin(x) + sin(y)) + (sin(x) - sin(y))/(cos(x) + (answered by solver91311)
Find each exact value of cos(x-y) if cos(x)=(5)/(12) and... (answered by jim_thompson5910)
If ( cos x+ isin x )(cos y+ isin y) = cos (y+x) + isin (y+x) Find the formula: Sin... (answered by ikleyn)
if cot(x+y) = 0, then sin( x+2y) =.... [ sin(x) , sin(y) , cos(2y) , cos(x) ] (answered by ikleyn)