A rational number is a number that can be expressed as the relationship between two integers. Fractions and decimals will either repeat or end. An example is 5. Maybe 7. 53573 is an example as well. So is 5/1, because 5 and 1 are both integers. so is 7.5, because 7 and 5 are both integers, and it ends (the numbers after the decimal doesn't keep going). Your answer is 7.8, because it ends.
B because -3 times -2 is positive six.
When doing something like this you want to make sure both sides are the same, so turn 7/4 into a percent. 7/4 equals 175, therefore they’re equal to each other.
We know that
if cos x is positive
and
sin x is negative
so
the angle x belong to the IV quadrant
cos x=5/13
we know that
sin²x+cos²x=1-------> sin²x=1-cos²x------> 1-(5/13)²---> 144/169
sin x=√(144/169)-------> sin x=12/13
but remember that x is on the IV quadrant
so
sin x=-12/13
Part A) <span>cos (x/2)
cos (x/2)=(+/-)</span>√[(1+cos x)/2]
cos (x/2)=(+/-)√[(1+5/13)/2]
cos (x/2)=(+/-)√[(18/13)/2]
cos (x/2)=(+/-)√[36/13]
cos (x/2)=(+/-)6/√13-------> cos (x/2)=(+/-)6√13/13
the angle (x/2) belong to the II quadrant
so
cos (x/2)=-6√√13/13
the answer Part A) is
cos (x/2)=-6√√13/13
Part B) sin (2x)
sin (2x)=2*sin x* cos x------> 2*[-12/13]*[5/13]----> -120/169
the answer Part B) is
sin(2x)=-120/169
Answer:
Step-by-step explanation:
