SOLUTION: I need help please im practicing for exams 1.)Find the absolute value of the complex number z=-8-12i 2)The exact value of sec 3pie/2 is what? 3)What is the domain of the fun

Algebra ->  Trigonometry-basics -> SOLUTION: I need help please im practicing for exams 1.)Find the absolute value of the complex number z=-8-12i 2)The exact value of sec 3pie/2 is what? 3)What is the domain of the fun      Log On


   

Question 761476: I need help please im practicing for exams

1.)Find the absolute value of the complex number z=-8-12i
2)The exact value of sec 3pie/2 is what?
3)What is the domain of the function f(x)=tan x
4)Find the exac value of sin inverse (sin 5pie/4)
5)whats the equivalence expression for the composition cot(arctan x)
6)whats the period of y=cos2x?
7)the phase shift of y=2sin(x+3)+1
8)The central angle theta subtended by an arc of length s=6cm on a circle of radius r=2cm find the area of the sectoe determined by theta.
16)csc78 deg 24’ is equivalent to what trigometric function
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
The absolute value of a complex number z=a%2Bbi is written as abs%28z%29
It is a nonnegative real number defined as:
abs%28z%29=sqrt%28a%5E2%2Bb%5E2%29
the absolute value of the complex number z=-8-12i will be
abs%28z%29=sqrt%28%28-8%29%5E2%2B%28-12%29%5E2%29
abs%28z%29=sqrt%2864%2B144%29
abs%28z%29=sqrt%28208%29
abs%28z%29=sqrt%2816%2A13%29
abs%28z%29=4sqrt%2813%29
2) The exact value of sec+%283pi%2F2%29 is infinity

3) What is the domain of the function f%28x%29=tan+%28x%29



4)Find the exact value of sin inverse (sin 5pie/4)
sin%5E-1+%28sin+%285pi%2F4%29%29=-pi%2F4 (result in radians)

5) whats the equivalence expression for the composition cot(arctan x)
cot%28arctan+%28x%29%29=cot%28tan%5E-1+%28x%29%29=1%2Fx
6) whats the period of y=cos%282x%29?
periodic in x with period pi
7) the phase shift of y=2sin%28x%2B3%29%2B1
it is periodic in x with period 2pi
phase shift: 3
vertical shift: 1
8)The central angle theta subtended by an arc of length s=6cm on a circle of radius r=2cm
find the area of the sector determined by theta.
circle central angle theta=s%2Fr
theta=6cm%2F2cm
theta=3
16)csc78 deg 24’ is equivalent to what trigonometric function
78° 24’ =78.4°
csc%2878.4%29°=1.020851