Answer:
A. 
General Formulas and Concepts:
<u>Trigonometry</u>
- [Right Triangles Only] SOHCAHTOA
- [Right Triangles Only] sinθ = opposite over hypotenuse
Step-by-step explanation:
<u>Step 1: Define</u>
sin 30°
<u>Step 2: Solve</u>
Since sin is opposite over hypotenuse, we need to find the length of the opposite leg of the angle and the length of the hypotenuse.
Given the triangle and it's values, the opposite leg to the 30° angle is 1 and the hypotenuse is 2.
Substituting it into sin, we have:
sin 30° = 1/2 = 0.5
∴ our answer is A.
<span>x 2 + 2x + 1 if you wanted is just 4x+1
</span>
Answer:
y = 3sin2t/2 - 3cos2t/4t + C/t
Step-by-step explanation:
The differential equation y' + 1/t y = 3 cos(2t) is a first order differential equation in the form y'+p(t)y = q(t) with integrating factor I = e^∫p(t)dt
Comparing the standard form with the given differential equation.
p(t) = 1/t and q(t) = 3cos(2t)
I = e^∫1/tdt
I = e^ln(t)
I = t
The general solution for first a first order DE is expressed as;
y×I = ∫q(t)Idt + C where I is the integrating factor and C is the constant of integration.
yt = ∫t(3cos2t)dt
yt = 3∫t(cos2t)dt ...... 1
Integrating ∫t(cos2t)dt using integration by part.
Let u = t, dv = cos2tdt
du/dt = 1; du = dt
v = ∫(cos2t)dt
v = sin2t/2
∫t(cos2t)dt = t(sin2t/2) + ∫(sin2t)/2dt
= tsin2t/2 - cos2t/4 ..... 2
Substituting equation 2 into 1
yt = 3(tsin2t/2 - cos2t/4) + C
Divide through by t
y = 3sin2t/2 - 3cos2t/4t + C/t
Hence the general solution to the ODE is y = 3sin2t/2 - 3cos2t/4t + C/t