This revolves around exact trig values - no easy way to say this, you just need to memorise them. They are there for sin cos and tan, but I will give you the main tan ones below - note this is RADIANS (always work in them when you can, everything is better):
tan0: 0
tanpi/6: 1/sqrt(3)
tanpi/4: 1
tanpi/3: sqrt(3)
tanpi/2: undefined
Now we just need to equate -2pi/3 to something we understand. 2pi/3 is 1/3 of the way round a circle, so -2pi/3 is 1/3 of the way round the circle going backwards (anticlockwise), so on a diagram we already know it's in the third quadrant of the circle (somewhere between pi and 3pi/2 rads).
We also know it is pi/3 away from pi, so we are looking at sqrt(3) or -sqrt(3) because of those exact values.
Now we just need to work out if it's positive or negative. You can look up a graph of tan and it'll show that the graph intercepts y at (0,0) and has a period of pi rads. Therefore between pi and 3pi/2 rads, the values of tan are positive. Therefore, this gives us our answer of sqrt(3).
A is the answer I would say
Answer:
<h2>10</h2>
Step-by-step explanation:
Given the expression 
. To find the product of this two values, the following steps must be followed.
According to one of the law of indices, 
The product is 10
Area = πr²
Area = 3.14* 6²
A = 3.14 * 36
A = 113.04
Now find the area of the other one.
<span>Area = πr²
A = 3.14 * 0.75</span>²
A = 1.76625
Now subtract them.
113.04 - 1.76625 = 111.27375
Now, we have our answer: A = <span>111.27375
However, I don't see why they told you to have an exact answer for the area. You can't have an exact answer when you use 3.14 for pi.</span>
