- #1
bradyj7
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Hello,
I'm studying for an exam and am stuck on a trigonometry question. Could anybody help me out?
The question is:
Solve the equation cos3x = 1/2, for x is an element of R, (where x is in radians)
The answer is:
x = pi/9 + 2npi/3
or
x = 5pi/9 + 2npi/3
where n is an element of Z
Sincere thanks
John
My attempt
Well we know that cos (pi/3) = 1/2
But cos 3x = 1/2 and are trying to figure out what x is.
So what times 3 will give you pi/3. That would be pi/6.
3 * (pi/6) = pi/3
cos (3*(pi/6)) = 1/2
I'm studying for an exam and am stuck on a trigonometry question. Could anybody help me out?
The question is:
Solve the equation cos3x = 1/2, for x is an element of R, (where x is in radians)
The answer is:
x = pi/9 + 2npi/3
or
x = 5pi/9 + 2npi/3
where n is an element of Z
Sincere thanks
John
My attempt
Well we know that cos (pi/3) = 1/2
But cos 3x = 1/2 and are trying to figure out what x is.
So what times 3 will give you pi/3. That would be pi/6.
3 * (pi/6) = pi/3
cos (3*(pi/6)) = 1/2