First we use sin(a+b)= sinacosb+sinbcosa
and cos(a+b)=cosa cosb -sinasinb
tan(x+pi/2)= sin(x+pi/2) / cos(x+pi/2)
and sin(x+pi/2) = sinxcospi/2 + sinpi/2cosx =cosx,
<span>cos(x+pi/2) = cosxcospi/2- sinxsinpi/2= - sinx,
</span> because <span>cospi/2 =0, </span>and <span>sinpi/2=1
</span><span>=tan(x+pi/2)= sin(x+pi/2) / cos(x+pi/2)= cosx / -sinx = -1/tanx = -cotx
</span>from where <span>tan(x+pi/2)=-cotx</span>
Answer: x= 20
Step-by-step explanation:
If m and n are parallel then the 3x and 2x+20 has to have the same measures which means they have to equal each other . So set them equal each other and solve for x.
2x + 20 = 3x
-2x -2x
20 = 1x
x= 20
9514 1404 393
Answer:
see below
Step-by-step explanation:
It is easiest to compare the equations when they are written in the same form.
The first set can be written in slope-intercept form.
y = 2x +7
y = 2x +7 . . . . add 2x
These equations are <em>identical</em>, so have infinitely many solutions.
__
The second set can be written in standard form.
y +4x = -5
y +4x = -10
These equations <em>differ only in their constant</em>, so have no solutions.
__
The third set is already written in slope-intercept form. The equations have <em>different slopes</em>, so have exactly one solution.
Isnt it letter D ? Not sure tho
Answer:
Step-by-step explanation:
1) Isosceles triangle
2) Right angled triangle
3) Scalene triangle
4) Equilateral triangle
5) Right angled triangle
6) Scalene triangle
7) Equilateral triangle
8) Scalene triangle
9) a) Equilateral triangle
9) b) Scalene triangle
9) c) Isosceles triangle
9) d) Right angled triangle
Note: Right angled triangle - If one angle is right angle, then it is Right angled triangle
Isosceles triangle: If two angles or two sides are equal, then it is Isosceles triangle.
Scalene triangle: If all three sides or three angles have different measurement, then it is Scalene triangle.
Equilateral triangle: If all the three sides are equal or all the three angles are equal, then it is Equilateral triangle
