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Express 3cos(x)+4sin(x) in the form Rsin(x+y) where you should explicitly determine R and y.

Since Rsin(x+y)=Rsin(x)cos(y)+Rsin(y)cos(x), we can set Rcos(y)=4 (1) and Rsin(y)=3 (2) on comparison to the desired equation. Considering (2) divided by (1) we see that tan(y)=sin(y)/cos(y)=3/4 so y=atan(3/...
WV
Answered by William V. • Maths tutor
12235 Views

How Do I Integrate cos(x) and sin(x) with higher powers?

The answer to this question depends on one thing, whether this power is odd or even. For even powers we use the identity cos(2x) = 2cos^2(x)-1 = 1-2sin^2(x). So for example, the integral of cos^2(x) is found...
CR
Answered by Ciarán R. • Maths tutor
12364 Views

differentiate: y^2 + 3xy + x + y = 8

dy/dx = 3x+1/ -2y-3x-1
GF
Answered by Gabrielle F. • Maths tutor
4854 Views

1/4 of a number is 20. What is 5 times the number?

400
GF
Answered by Gabrielle F. • Maths tutor
9309 Views

What is 2/7 of 70

20
GF
Answered by Gabrielle F. • Maths tutor
10568 Views