pre calc
posted by Anonymous .
use an appropriate halfangle formula to find the exact value ofthe expression.
tan22.5
write the product as a sum
sinxsin5x
write the sum as a product
sin2xsin7x

pre calc 
JQuiroz
sinxsin5x
sinucosv= 1/2[cos(uv)cos(u+v)]
= 1/2[cos(x5x)cos(x+5x)]
= 1/2[cos(4x)cos(6x)]
= 1/2cos4x1/2cos6x
Respond to this Question
Similar Questions

math
Find the two numbers that multiply to the product number and add to the sum number of the following: a)Product 563033256; Sum 51895 b)Product 43481220; Sum 28429 c)Product 2545124358; Sum 105619 I tried xy = product and x+y = sum, … 
Math (Calc)
Find the Exact value of Pi/24. I'm not sure whether to use a halfangle formula or a difference/sum of angles formula. 
MATH
1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL STEPS) sin 2x  sin x = 0 2.) GIVEN: sin u = 3/5, 0 < u < ï/2 Find the exact values of: sin 2u, cos 2u and tan 2u using the doubleangle formulas. 3.)Use … 
pre calc
Use the sumtoproduct formula to simplify the expression: If sin 52 + sin 8 = sin A, 0<A<90, then A =? 
Math
1. use the suitable producttosum formula to rewrite the following expression: sin(13x/2)sin(5x/2) 2. Find value of cos(255degrees)cos(105degrees) is it 1/4? 
Math
Use the producttosum formulas to write the product as a sum or difference. sin(x+y) * cos(xy) 
Algebra 2
Q: Write a quadratic equation with integral coefficients whose roots are 6+i and 6i My Answer: x^2+12x+37 (first) sum=12 product=37 (then) write equation using formula x^2(sum)x+product Is my work and answer correct? 
Pre Calculus
Use the sumtoproduct formulas to find the exact value of the given expression. sin 150° + sin 30° 
maths
Use the producttosum formula to write the given product as a sum or difference. 6sin π/10 cos π/ 10 
Math
A. Write 60 as the sum of two numbers. B. Write 60 as the product of two numbers. C. Write 60 as the product of two factors. In youe expression, write one of the factors as a sum of two numbers. Find an equivalent way to write this …