The equation for finding the area of a circle of A=pi(r^2). Just plug in r=4 to find the area:
A=pi(4^2)
A=16pi
A=50.27 units squared
If A is QIV, then 3π/2 ≤A≤2π;
we have to find out in what quadrant is A/2
(3π/2)/2≤A/2≤(2π)/2 ⇒ 3π/4≤A/2≤π
We can see that A/2 will be in QIII; therefore the sec (A/2) will be negative (-).
1) we have to calculate cos (A/2)
Cos (A/2)=⁺₋√[(1+cos A/2)/2]
We choose this formula: Cos (A/2)= -√[(1+cos A/2)/2], because sec A/2 is in quadrant Q III, and the secant (sec A/2=1/cos A/2) in this quadrant is negative.
Cos (A/2)=-√[(1+cos A)/2]=-√[(1+(1/2)]/2=-√(3/4)=-(√3)/2.
2) we compute the sec (A/2)
Data:
cos (A/2)=-(√3)/2
sec (A/2)=1/cos (A/2)
sec (A/2)=1/(-(√3)/2)=-2/√3=-(2√3)/3
Answer: sec (A/2)=-(2√3)/3
Answer: 150
Step-by-step explanation:
Let x be the unknown number
12% of x= 18
that is; 12/100 * x = 18
12x/100 = 18
cross multiply
12x = 18 * 100
12x = 1800
divide both sides by 12
x = 1800/12
x = 150
Answer:
96.82
Step-by-step explanation:
Area = (ab × sin C)/2
