Answer:
tan(2u)=[4sqrt(21)]/[17]
Step-by-step explanation:
Let u=arcsin(0.4)
tan(2u)=sin(2u)/cos(2u)
tan(2u)=[2sin(u)cos(u)]/[cos^2(u)-sin^2(u)]
If u=arcsin(0.4), then sin(u)=0.4
By the Pythagorean Identity, cos^2(u)+sin^2(u)=1, we have cos^2(u)=1-sin^2(u)=1-(0.4)^2=1-0.16=0.84.
This also implies cos(u)=sqrt(0.84) since cosine is positive.
Plug in values:
tan(2u)=[2(0.4)(sqrt(0.84)]/[0.84-0.16]
tan(2u)=[2(0.4)(sqrt(0.84)]/[0.68]
tan(2u)=[(0.4)(sqrt(0.84)]/[0.34]
tan(2u)=[(40)(sqrt(0.84)]/[34]
tan(2u)=[(20)(sqrt(0.84)]/[17]
Note:
0.84=0.04(21)
So the principal square root of 0.04 is 0.2
Sqrt(0.84)=0.2sqrt(21).
tan(2u)=[(20)(0.2)(sqrt(21)]/[17]
tan(2u)=[(20)(2)sqrt(21)]/[170]
tan(2u)=[(2)(2)sqrt(21)]/[17]
tan(2u)=[4sqrt(21)]/[17]
5 + 5 + 5 + 5 equals 550 lgjf8654
Answer: The solution is the ordered pair (1/2, -3/4) so x = 1/2 and y = -3/4 pair up together. The two lines, when graphed, cross at this location.
note: 1/2 = 0.5 and -3/4 = -0.75; so the intersection point can be written as (0.5, -0.75)
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Explanation:
The second equation has y isolated. We can replace the y in the first equation with the expression 1/2x - 1
3x + 2y = 0
3x + 2( y ) = 0
3x + 2( 1/2x - 1) = 0 ... y is replaced with 1/2x-1
3x + 2(1/2x) + 2(-1) = 0 .... distribute
3x + x - 2 = 0 .... note how 2 times 1/2 is 1
4x - 2 = 0
4x = 2
x = 2/4
x = 1/2
Use this x value to find the y value it pairs with
y = (1/2)*x - 1
y = (1/2)*(1/2) - 1 ... replace x with 1/2
y = 1/4 - 1
y = 1/4 - 4/4
y = (1-4)/4
y = -3/4
Move each point over two times
