Solving Trigonometic Equations

1)sinx = (4/5)

2) cosx = (-12/13)

Solving Trigonometic Equations
1)sinx = (4/5)

2) cosx = (-12/13)

What is the question? Solve for x?

x= arcsin (4/5) put that in your calculator.

Same for the next.

For both cases I recognize the sides of well-known right-angled triangles: {3,4,5} and {5,12,13}

As bobpursley said, you did not ask what should be done.

One type of question would be to give the other 2 trig ratios for acute angles, or

find all solutions for the angle x in a given domain.

There should be detailed and fully explained example of this type of question in your text book

Did they teach you a memory aid called CAST ? It makes this topic very easy

Solve for x , please