If cos theta =-2/3, which of the following are possible
1 answer:
Well, the cos(∅) is negative in the second and third quadrants. If you are solving for theta, you would use the inverse of the cos or arccos
take the inverse of both sides to get:
x = arccos(-2/3) now evaluate the right
x = 131.8103149 degrees
to find your second solution, subtract your reference angle from 360 degrees.
360 - 131.8103149 = 228.1896851 degrees
Now the period of cos is 2π or 360 degrees. So if you want to consider all possible solutions, you would need to add/subtract 360n to both solutions above..
Not sure if this is what you're looking for, but thought I would leave it here for you just in case... As a side note, you could do this problem in radian measurement as well.
x = arccos(-2/3) now evaluate the right
x = 131.8103149 degrees
to find your second solution, subtract your reference angle from 360 degrees.
360 - 131.8103149 = 228.1896851 degrees
Now the period of cos is 2π or 360 degrees. So if you want to consider all possible solutions, you would need to add/subtract 360n to both solutions above..
Not sure if this is what you're looking for, but thought I would leave it here for you just in case... As a side note, you could do this problem in radian measurement as well.
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Answer:
See description below.
Step-by-step explanation:
To choose the correct equation, find the slope of the line on the graph. Identify two points on the line. Then subtract to find their rate of change using the slope formula.
When you know the slope, find the negative reciprocal. For example, if the slope is 2/1 then the negative reciprocal is -1/2. This is the slope of a perpendicular line to a line with slope 2. Choose the equation which has this same slope.
Example:
y = 2x -1
y= -1/2 +5
so, is a semi-circle, half a circle, recall a circle has a total of 360°, so half of that will be 180°.
the diameter of that circle is 10, so its radius is half that, or 5.