How do you solve #tan(x+pi)+2sin(x+pi)=0#?

1 Answer
Jul 31, 2016

For this type of problem, you must use the double angle formulae to expand the parentheses.

Explanation:

The following formulas are extremely important. Be sure to retain them into the future.

http://study.com/academy/lesson/applying-the-sum-difference-identities.html

Now, using these formulae, we can expand:

#(tan(x) + tan(pi))/(1 - tanxtanpi) + 2(sinxcospi + cosxsinpi) = 0#

#(tanx + 0)/(1 - tanx xx 0) + 2(sinx(-1) + cosx(0)) = 0#

#tanx/1 + 2(-sinx) = 0#

#tanx - 2sinx = 0#

#sinx/cosx - 2sinx =0#

#(sinx -2sinxcosx)/cosx = 0#

#sinx - 2sinxcosx = 0 xx cosx#

#sinx(1 - 2cosx) = 0#

#sinx = 0 and cosx = 1/2#

#x = 0˚, 180˚, 60˚ and 300˚#

Note that these solutions are only in the interval #0˚ <= x <360˚#.

Hopefully this helps!