Answer:
Option 3 is right.
Step-by-step explanation:
Reference angle of x is obtained by either 180-x, 180+x. or 360-x depending on the posiiton of terminal whether II quadrant or iv quadrant, or iii quadrant, etc.
In whatever way we find reference angles,
cos will remain cos only and sin will remain sin only there may be only changes in sign.
Of all the ordered pairs given, we find that I, II, and Iv there is a switch over form cos to sine and sin to cos. Hence these options cannot be for reference angles.
III option is 
show that both sign and cos changed sign. This is possible only in III quadrant.
ie reference angle of orignal angle t = 180+t
SO this option is right.
Answer:
Fourth option.
Sixth option.
Step-by-step explanation:
We know that:
- Any number you can find on the number line, is a Real number.
- Integers contains positive numbers, negative numbers and zero. Every Integer is a Rational number.
- A Rational number is that number that can be written in the following form:

Where "a" and "b" are integers (
).
- An Irrational number cannot be written as a simple fraction.
- A Whole number is any of the numbers {
}. Every Whole number is a Rational number.
- Natural numbers contain the set of positive integers{
} or to the set of nonnegative integers {
}, Every Natural number is a Rational number.
Based on this, since
is in the form
where
and
, it is a Rational Number and therefore a Real number.
Answer:
9×10,000+4×10 eauals to 90,040