Answer:
Mostly correct
For Q3, you are doing great, you remembered that negative numbers can happen if the exponent is an odd number.
For Q4, I think you were confused with the fractions,
4(i)
4(ii) is also wrong but I'll let you try to fix it yourself following what I given you for 4(i). You should get 1/64
Hope this helps!
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Explanation:
Recall that the pythagorean trig identity is
If we were to isolate sine, then,
We don't have to worry about the plus minus because sine is positive when 0 < x < pi/2.
Through similar calculations,
Cosine is also positive in this quadrant.
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So,
Therefore,
is an identity as long as 0 < x < pi/2