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Trigonometric Equation Help (1 Viewer)
- Thread starter FesuY
- Start date
You could shift the domain to something that is easier for questions for example 
Say for question a originally you would have to solve=1)
for 
but by shifting the domain by pi forward you get )=1)
for 
which can be further modified to match what is in the cos function \leq{4}\pi)
.
After solving the equation a little, you should arrive at
=\frac{\pi}{3}, \frac{5\pi}{3}, \frac{7\pi}{3}, \frac{11\pi}{3}\\\\x=-\frac{5\pi}{6},-\frac{\pi}{6}, \frac{\pi}{6}, \frac{5\pi}{6})
Which is in the required domain.
Say for question a originally you would have to solve
After solving the equation a little, you should arrive at
Which is in the required domain.
FesuY
Active Member
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- HSC
- 2022
Thats what I thought, however for this question the answer is 90, -150 and -30, and my answer was 90, 210, -150 and -30You could shift the domain to something that is easier for questions for example
Say for question a originally you would have to solve
After solving the equation a little, you should arrive at
Which is in the required domain.
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Assuming the same domain applies as the previous equation
Thus solving for
So the 210 is not included.
You could also look at the original domain and see of the answers fit within it, since 210 does not fit within the original domain you you can disregard it.