Try this solution:
for the circle A: circumference=6π, area=9π
for the circle B: circumference=12π, area=36π
PS. formula for circumference is 'L=2πr', for area is 'S=πr²'.
Answer:
x = -2
, y = 3
Step-by-step explanation:
Solve the following system:
{4 x + 5 y = 7
y = 3 x + 9
Hint: | Perform a substitution.
Substitute y = 3 x + 9 into the first equation:
{4 x + 5 (3 x + 9) = 7
y = 3 x + 9
Hint: | Expand the left hand side of the equation 4 x + 5 (3 x + 9) = 7.
4 x + 5 (3 x + 9) = (15 x + 45) + 4 x = 19 x + 45:
{19 x + 45 = 7
y = 3 x + 9
Hint: | Choose an equation and a variable to solve for.
In the first equation, look to solve for x:
{19 x + 45 = 7
y = 3 x + 9
Hint: | Isolate terms with x to the left hand side.
Subtract 45 from both sides:
{19 x = -38
y = 3 x + 9
Hint: | Solve for x.
Divide both sides by 19:
{x = -2
y = 3 x + 9
Hint: | Perform a back substitution.
Substitute x = -2 into the second equation:
Answer: {x = -2
, y = 3
What you need to do is first multiplying by using the Foil method. <u>The foil method is multiplying the terms which occur last in each binomial</u>
Than you combine the real imaginary parts of the expression. so the Answer is
49 - 43i Hope this helps :)
Remark
<u>Two facts.</u>
1) Tan(x) = Sin(x) / Cos(x)
2) Csc(x) and Sin(x) are reciprocal relationships. When multiplied together, they equal 1.
Solution
So Csc(x) * tan(x) = csc(x) * sin(x) / cos(x) = 1/cos(x) = sec(x)
So far what we have is tan^2(x) + sec(x). We have to get rid of tan^2(x)
Use the identity of 1 + tan^2(x) = sec^2(x)
tan^2(x) = sec^2(x) - 1
sec^2(x) - 1 + sec(x)
a^2 + a - 1 <<<<<< Answer
B is the answer.
