What are two angles within 0°-360° that has a cosine of negative root three over 2? Show work please
1 answer:
Answer:
150° and 210°
Step-by-step explanation:
1) according to the condition the required cosine is <0, it means the required angles are in the II-d and III-d quaters (see the attached picture no. 1);
2) it is known, that arccos(√3/2)=30°- the angle is between 0° and 90°, - but the requred angles are between 90° and 270° (see the picture no. 2), then
3) (angle)₁=180°-arccos(√3/2) and (angle)₂=180°+arccos(√3/2), then finally
(angle)₁=180°-30°=150°; (angle)₂=180°+30°=210°.
PS. note, the suggested way is not the only one.
You might be interested in
Answer:
x = 3 + √6 ; x = 3 - √6 ; ;
Step-by-step explanation:
Relation given in the question:
(x² − 6x +3)(2x² − 4x − 7) = 0
Now,
for the above relation to be true the following condition must be followed:
Either (x² − 6x +3) = 0 ............(1)
or
(2x² − 4x − 7) = 0 ..........(2)
now considering the equation (1)
(x² − 6x +3) = 0
the roots can be found out as:
for the equation ax² + bx + c = 0
thus,
the roots are
or
or
and, x =
or
and, x =
or
x = 3 + √6 and x = 3 - √6
similarly for (2x² − 4x − 7) = 0.
we have
the roots are
or
or
and, x =
or
and, x =
or
and, x =
or
and,
Hence, the possible roots are
x = 3 + √6 ; x = 3 - √6 ; ;
Answer:
(4,0)
Step-by-step explanation:
The object is first at (0,0)
It is reflected across line x=-2, this means you draw the mirror line at x=-2 and count 2 equal units backwards to get the image.The image will be at ;
The image (-4,0) is then reflected on the y-axis
You know reflection on the y-axis, the y-coordinate remains the same but the x-coordinate is changed to its opposite sign.
Hence;
(- -4,0)= (4,0)
The image will move 8 units towards positive x-axis.This is the same as moving 4 units from the mirror line at (0,0) and land at (4,0)