The answer is 169 because 180-11=169
Answer:
N = 3
Step-by-step explanation:
I don't know what the whole thing above is, but just disregard that.
All it is here is cross multiplication.
So 28N = 21 * 4
Multiply...
28N = 84
And divide each side by 28
N = 3
Since ur using r as a variable the answer is r = 7.
Answer:
x-coordinate = 0
Step-by-step explanation:
In a coordinate plan there are two perpendicular lines one is x-axis and another is y-axis
x-axis is a horizontal line and y-axis is a vertical line.
Both lines intersect each other at (0,0).
On x-axis, y-coordinate remains same , i.e., y=0.
On y-axis, x-coordinate remains same , i.e., x=0.
Therefore, the x co-ordinate of any point lying on the y axis is 0.
T=-1
sinA=sin(π/2-3A), A=2nπ+π/2-3A, 4A=2nπ+π/2, A=nπ/2+π/8 where n is an integer.
Also, π-A=2nπ+π/2-3A, 2A=2nπ-π/2, A=nπ-π/4.
The hard way:
cos3A=cos(2A+A)=cos(2A)cosA-sin(2A)sinA.
Let s=sinA and c=cosA, then s²+c²=1.
cos3A=(2c²-1)c-2c(1-c²)=c(4c²-3).
s=c(4c²-3) is the original equation.
Let t=tanA=s/c, then c²=1/(1+t²).
t=4c²-3=4/(1+t²)-3=(4-3-3t²)/(1+t²)=(1-3t²)/(1+t²).
So t+t³=1-3t², t³+3t²+t-1=0=(t+1)(t²+2t-1).
So t=-1 is a solution.
t²+2t-1=0 is a solution, t²+2t+1-1-1=0=(t+1)²-2, so t=-1+√2 and t=-1-√2 are solutions.
Therefore tanA=-1, -1+√2, -1-√2 are the three solutions from which:
A=-π/4, π/8, -3π/8 radians and these values +2πn where n is an integer.
Replacing π by 180° converts the solutions to degrees.
