answersLogoWhite

0

According to de Moivre's formula,

cos3x + isin3x = (cosx + isinx)3 = cos3x + 3cos2x*isinx + 3cosx*i2sin2x + i3sin3x

Comparing the imaginary parts,

isin3x = 3cos2x*isinx + i3sin3x

so that sin3x = 3cos2x*sinx - sin3x

= 3*(1-sin2x)sinx - sin3x

= 3sinx - 4sin3x

User Avatar

Wiki User

12y ago

What else can I help you with?

Related Questions

What is arithmetic tree?

an arithmetic tree an is formula using prime and composite number to express its factors.


What is the formula for finding area of irregular shape?

You can use Riemann sums. If you can express your shape using a set of points (x_i,y_i), you can express the area as: area = area + y_i * (x(i+1)-x(i-1))


How would you express the following using symbols three formula units of magnesium bromide?

MgBr2 (s) - This symbol represents three formula units of magnesium bromide, where Mg is magnesium and Br is bromide.


How do you express the area of a circle as a function of its circumference?

By using the well-known formula, A = pi x r2, and expressing the radius in terms of the circumference, r = c / (2 x pi). Replace in the first formula, and simplify. f


How can one obtain an American Express Credit Card Log In?

Someone that has an American Express credit card can login using the information on it by using the American Express website. The American Express website allows one to track and access their credit cards.


What is a chemical formula using neon?

Formula: Ne


What states a rule using variables?

A Formula


What is theater and what does it mean to you?

Theater is a way to express yourself by acting. By using your role and charteristics of that character, you can express yourself by using what you know or have experienced about it. You show in your perspective of the role how you would have done it. You express it in your own way.


Sin3alfa equals to?

The expression (\sin(3\alpha)) can be expanded using the triple angle formula for sine, which is (\sin(3\alpha) = 3\sin(\alpha) - 4\sin^3(\alpha)). This formula allows you to express (\sin(3\alpha)) in terms of (\sin(\alpha)).


What is a simple sentence using the word chemical formula?

This is a simple sentence using the words "chemical formula".


What is used to express wind speed?

You can express or determine the speed of wind using the Beaufort Wind Scale.


People express thoughts mainly by using what?

language