Update the question so it's on-topic for Mathematics Stack Exchange. Closed 4 years ago. How many words can be made by using the letters of the word ENGLAND such that words begin and end with a vowel? I couldn't understand how come the answer to this question is 120
Answer:
20 votes
Step-by-step explanation:
You start with the percents: You always start with 100%
100-5=95
Then you multiply
95 x 4
4 is how many votes he received the 2nd time
95 x 4= 380
Then you subtract
380-360= 20
Your Welcome :)
Answer:
308°
Step-by-step explanation:
It's a Reflex angle more than 180° but less than 360°.......hope this helps have a great day/night
Answer:
The greatest prime factor of 38 is 19
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
