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]
The answer is 1 19/80 or 1.2375.
Hope this helps!
Answer:
k = 25
Step-by-step explanation:
(2x - sqrt(k) )^2 Expand this as a binomial
4x^2 - 4x*sqrt(k) + k The middle term must be -20x Solve for k so it is
-4xsqrt(k) = - 20x Divide by -4x
sqrt(k) = -20x/-4x Do the division
sqrt(k) = 5 Square both sides
k = 25
Leap years have 366 days, and there are 8 pints per gallon. So we divide the 366 days by the 8 pints per 1 gallon. We end up getting:
45.75 gallons in 1 leap year.