Trig Functions- Could anyone tell me why my working is wrong?

In summary, the person is trying to solve 2cosx-(sqrt(3))cosx sinx = 0 for (-pie<=x<=pie) and is struggling because they are dividing through by cos x. However, this statement is flawed as there is no value for sin x= 2/(sqrt(3)). They eventually realize that they can find the answer for the cosine part, which is cos x = 0. They also mention that the other possibility is not possible. The correct answers are pie/2 and -pie/2.
  • #1
ku1005
66
0
Trig Functions- Could anyone tell me why my working is wrong??

the question seems simple..although i don't know what i am doing because it is obviously wrong!. thnkas heaps if anyone can help..

solve
2cosx-(sqrt(3))cosx sinx = 0 for (-pie<=x<=pie)

what i was doing is dividing through by cos x, therefore i obtain:

2-(sqrt(3))sinx= 0

however this statement is flawed! since no value exists for sin x= 2/(sqrt(3))

?it seems simple.. so wat am i doing wrong!1
 
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  • #2
ku1005 said:
the question seems simple..although i don't know what i am doing because it is obviously wrong!. thnkas heaps if anyone can help..

solve
2cosx-(sqrt(3))cosx sinx = 0 for (-pie<=x<=pie)

what i was doing is dividing through by cos x, therefore i obtain:

2-(sqrt(3))sinx= 0

however this statement is flawed! since no value exists for sin x= 2/(sqrt(3))

?it seems simple.. so wat am i doing wrong!1

if you copied the question right then yes sin x = 2/srqt3 is not possible

however you CAN find answer for the cosine part
cos x = 0 what values of x will do?
 
  • #3
yep got it now...instead i just did the follwing
=
cosx(2-(sqrt(3))sinx)=0
therfore either cosx= 0 (as u stated above) or the other applies...which isnlt possible...so yeah obviously the answers are pie/2 and -pie/2
thanks for your help!
 

What are trigonometric functions?

Trigonometric functions are mathematical functions that relate the angles and sides of a triangle. They are commonly used in geometry, physics, and engineering.

What are the main trigonometric functions?

The main trigonometric functions are sine, cosine, tangent, secant, cosecant, and cotangent. These functions are used to calculate the ratios of the sides of a right triangle.

How do I find the values of trigonometric functions?

The values of trigonometric functions can be found by using a calculator or by using trigonometric tables. These values can also be calculated using the sides and angles of a right triangle.

What are the common mistakes when working with trigonometric functions?

Some common mistakes when working with trigonometric functions include using the wrong formula, forgetting to convert angles from degrees to radians, and not properly labeling the sides of the triangle.

How can I check if my working with trigonometric functions is correct?

You can check your working with trigonometric functions by using a calculator to verify your answers, double-checking your formulas, and labeling your triangle correctly. It is also helpful to have someone else review your work for any potential errors.

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