How do I do part b?
When part a is :
cos(θ+30) = 0.5
cos^-1 cos(θ+30) = cos^-1 (0.5)
Using cast diagram for cosine (360-theta)
θ+30 = 60 , 300
θ = 30 ,270
#Highschool Trig (double angle and addition formulae)
still rune
sonic gladeBOT
How do I do part b?
When part a is :
cos(θ+30) = 0.5
cos^-1 cos(θ+30) = cos^-...
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still rune
The question is a follow on from part a, try finding another way to write cos30 and sin30!
unkempt galleon
Hint:Try taking sin(theta) to the other side and squaring both sides
safe iron
second problem is quite a standard one, so whenever u see this type try to do this :- a*cos(x) - b*sin(x) = 1
then multiply both sides by sqrt(a^2+b^2), so for this problem it becomes :-
sqrt(3)/2 * cosx - 1/2 * sinx = 2
now write sqrt(3)/2 in terms of cos and 1/2 in terms of sin to get the cos(A+B) formulae
unkempt galleon
Is it a nust that we need to solve it by the help of A,except that the interval is from A
plain pagodaBOT
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jade crescent
second problem is quite a standard one, so whenever u see this type try to do th...
This is a valid method (and a general one to solve, at that) but the RHS should be 1/2, not 2. Besides, I believe, similar to spusho, that it is meant to be a follow up on part a). Tackling it with this method is not optimal given the context.
unkempt galleon
Well then shifting sides and squaring both and going for middle term factorization should be it