Question #d6098

1 Answer
Oct 21, 2017

#A~~-2.36#

Explanation:

We know #tan(A + B) = −4# and #tan B = 5/3#

Solving for B:

#tan B=5/3#

#B=arctan(5/3)# Note: Arctan is the same as inverse tan

Substituting it into the first equation:

#tan(A + B) = −4#

#tan(A + arctan(5/3)) = −4#

#A + arctan(5/3) =arctan(−4)#

#A=arctan(-4)-arctan(5/3)#

Plug into calculator:

#A=-2.35619449~~-2.36#