Solve SinA- tanA=0?
3 Answers
Explanation:
But,
Hence, we need to consider
But,
The solution is
Explanation:
The equation is
Therefore,
The solution is
Explanation:
The first step is to find a way where we can have only have one trig function in the equation. Remember that cosine and secant are reciprocals (can be readily written as one or the other). Now you can take advantage of pythagorean identities:
#sqrt(1 - cos^2A) = tanA#
Square both sides:
#1 - cos^2A = tan^2A#
Now recall that
#1- cos^2A =sec^2A - 1#
#2 = 1/cos^2A + cos^2A#
#2 = (1 + cos^4A)/cos^2A#
#2cos^2A = cos^4A + 1#
#0 = cos^4A - 2cos^2A + 1#
This is a simple perfect square trinomial.
#0 = (cos^2A - 1)^2#
#cosA = +- 1#
#A = 0 or pi-> A = pin#
Hopefully this helps!