On this page sin3A cos3A tan3A formulas we are going to see the formulas in trigonometry.These are the formulas that we are using in trigonometry to simplify.
Here you can find example problems to show the purpose of these formulas.
Now we are going to see example problems based on the above formulas.
If sin A = 3/5 then find the value of sin 3A.
In this problem we have given the value of Sin A. Now we need to find the value of sin 3A.
To solve this problem we have a formula for sin 3A.In this
formula we have to plug 3/5 instead of the term sin A.
Sin 3A = 3 Sin A - 4 sin³A
sin 3A = 3 (3/5) - 4 (3/5)³
sin 3A = 9/5 - 4 (9/25)
= 9/5 - 36/25
= (9/5) x (5/5) - 3/25
= 45/25 - 3/25
Example 2 :
Prove that 8 cos³
Π/9 - 6 cos
Π/9 = 1
8 cos³ Π/9 - 6 cos Π/9 = 1
To solve this problem, first we have factor out from both terms.We can split 8 as 2 times 4 and 6 as 2 times 3. After factor out 3 it looks like a formula.
2[4cos³ Π/9 - 3 cos Π/9]
Cos 3A = 4 Cos³A - 3 Cos A
= 2[4cos³ Π/9 - 3 cos Π/9]
= 2cos 3(Π/9)
= 2cos (3Π/9)
= 2cos Π/3
= 2 x v3/2 ==> v3
Example 3 :
If tan A = 3 find the value of tan 3A
tan 3A = (3 tan A - tan³ A)/(1-3tan²A)
= [3 (3) - (3)³] /[1-3(3)²]
= [9 - 27]/[1-27]
After having gone through the stuff, we hope that the students would have understood "Sin3A cos3A tan3A formulas"
Apart from the stuff given above, if you want to know more about "Sin3A cos3A tan3A formulas", please click here
Apart from the stuff given in this section, if you need any other stuff in math, please use our google custom search here.
If you have any feedback about our math content, please mail us :
We always appreciate your feedback.
You can also visit the following web pages on different stuff in math.
Negative exponents rules
APTITUDE TESTS ONLINE
ACT MATH ONLINE TEST
TRANSFORMATIONS OF FUNCTIONS
ORDER OF OPERATIONS
MATH FOR KIDS
Word problems on linear equations
Trigonometry word problems
Word problems on mixed fractrions
Ratio and proportion shortcuts
Converting repeating decimals in to fractions