ImAnEngineer said:
If it's a joke... sorry but I don't get it.tiny-tim said:Not how, but Howe … Julia Ward Howe, in 1861, derived them, and they became a Civil War marching song, to the tune now known as the Battle Hymn of the Republic.
ImAnEngineer said:
tiny-tim said:
try singing it!
The three basic trig sum formulas are:
1. sin(A + B) = sin A cos B + cos A sin B
2. cos(A + B) = cos A cos B - sin A sin B
3. tan(A + B) = (tan A + tan B) / (1 - tan A tan B)
These formulas are used to find the sine, cosine, and tangent of the sum of two angles.
The trig sum formulas can be derived from the addition formulas for sine, cosine, and tangent. These addition formulas state that:
1. sin(A + B) = sin A cos B + cos A sin B
2. cos(A + B) = cos A cos B - sin A sin B
3. tan(A + B) = (tan A + tan B) / (1 - tan A tan B)
By substituting A = x and B = y in these formulas, we can obtain the trig sum formulas.
The main purpose of using trig sum formulas is to simplify trigonometric expressions involving sums of angles. These formulas can also be used to solve trigonometric equations, simplify complex numbers, and prove identities.
Yes, there are many other useful trig sum formulas, such as the double angle formulas and half angle formulas. These formulas are used to find the sine, cosine, and tangent of double or half of an angle.
One way to memorize the trig sum formulas is to understand how they are derived. You can also create your own mnemonics or use flashcards to help you remember the formulas. Practice using the formulas in different problems to reinforce your understanding and memorization.