Maths
posted by Karla
Hey :)
I was wondering if someone could tell me if this answer and working is correct or not...
Cos theta =0.25
Cos inverse 0.25 = 14
therefore theta equals:
18014=194or/and
180+14=166
Any help would be much appreciated :)
Thanks!

Jai
cos (theta) = 0.25
theta = cos^1 (0.25)
there are two answers:
theta = 104.48 degrees = 3.65 radians
and,
theta = 104.48 degrees = 3.65 radians
hope this helps~ :) 
Reiny
Usually the required angles are in the domain of
0 ≤ Ø ≤ 360°
Since the given cosØ is negative, by the CAST rule,
Ø must be in either quadrant II or III
from cosØ = +.25 we get the reference angle of 75.52°
so Ø = 180°75.52° or 104.48° (Jai's answer)
or Ø = 180°+75.52° or 255.52°
Since the period of cosØ is 360°, you can get other answers by adding or subtracting multiples of 360°
(For Jai's second answer, 255.52  360° = 104.48°)
I have no idea how you came up with
inverse cos (.25) = 14
Respond to this Question
Similar Questions

algebra
Can someone please help me do this problem? 
Calculus
I wanted to confirm that I solved these problems correctly (we had to convert the polar curves to Cartesian equations). 1.rcos(theta)=1 x=1 2.r=2*sin(theta)+2*cos(theta) r^2=2rsin(theta)+2rcos(theta) x^2+y^2=2y+2x (a little unsure … 
Pre Calc.
Use the sum or difference identity to find the exact value of sin255 degrees. My answer: (sqrt(2) sqrt(6)) / (4) Find the value of tan (alphabeta), if cos alpha= 3/5, sin beta= 5/13, 90<alpha<180, and 90<beta<180. My … 
Physics
An object is shot at 20m/s at an angle theta. The object lands 24m away. What is the angle? 
trigonomtry
can you correct the rest for me please? Express each as a function of theta: a. sin (270deg + theta)= cos theta b. cos (pi + theta)= cos theta c. tan (810 + theta)= ? 
trigonometry
can you correct the rest for me please? Express each as a function of theta: a. sin (270deg + theta)= cos theta b. cos (pi + theta)= cos theta c. tan (810 + theta)= ? 
trigonometry
can you correct the rest for me please? Express each as a function of theta: a. sin (270deg + theta)= cos theta b. cos (pi + theta)= cos theta c. tan (810 + theta)= ? 
Trigonometry (repost Reiny)
at 1:35am I posted ; Write equivalent equations in the form of inverse functions for a.)x=y+cos theta b.)cosy=x^2 my answers were a.) x= y+ cos theta cos theta = xy theta = cos^1(xy) b.) cosy=x^2 cos(y) = x^2 y = Cos^1(x^2) your … 
Math (Calculus)
Given any Cartesian coordinates, (x,y), there are polar coordinates (r,theta) with –pi/2< theta < pi/2. Find polar coordinates with –pi/2 < theta < pi/2 for the following Cartesian coordinate: If (x,y) = (11,–7) then … 
Algebra II
Multiple Choice (theta) means the symbol 0 with the dash in it. 1.)Which expression is equivalent to tan(theta)(sec(theta))/(sin(theta))?