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.
Example 1:
If sin A = 3/5 then find the value of sin 3A.
Solution :
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
= (45-3)/25
= 42/25
Example 2 :
Prove that 8 cos³
Π/9 - 6 cos
Π/9 = 1
Solution :
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
Solution :
tan 3A = (3 tan A - tan³ A)/(1-3tan²A)
= [3 (3) - (3)³] /[1-3(3)²]
= [9 - 27]/[1-27]
= (-18)/(-26)
= 9/13
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.
WORD PROBLEMS
HCF and LCM word problems
Word problems on simple equations
Word problems on linear equations
Word problems on quadratic equations
Area and perimeter word problems
Word problems on direct variation and inverse variation
Word problems on comparing rates
Converting customary units word problems
Converting metric units word problems
Word problems on simple interest
Word problems on compound interest
Word problems on types of angles
Complementary and supplementary angles word problems
Markup and markdown word problems
Word problems on mixed fractrions
One step equation word problems
Linear inequalities word problems
Ratio and proportion word problems
Word problems on sets and venn diagrams
Pythagorean theorem word problems
Percent of a number word problems
Word problems on constant speed
Word problems on average speed
Word problems on sum of the angles of a triangle is 180 degree
OTHER TOPICS
Time, speed and distance shortcuts
Ratio and proportion shortcuts
Domain and range of rational functions
Domain and range of rational functions with holes
Graphing rational functions with holes
Converting repeating decimals in to fractions
Decimal representation of rational numbers
Finding square root using long division
L.C.M method to solve time and work problems
Translating the word problems in to algebraic expressions
Remainder when 2 power 256 is divided by 17
Remainder when 17 power 23 is divided by 16
Sum of all three digit numbers divisible by 6
Sum of all three digit numbers divisible by 7
Sum of all three digit numbers divisible by 8
Sum of all three digit numbers formed using 1, 3, 4
Sum of all three four digit numbers formed with non zero digits