taja19 taja19
  • 12-08-2019
  • Mathematics
contestada

Simplify the expression by using a double-angle formula.
cos-39°– sin²39

Respuesta :

Аноним Аноним
  • 13-08-2019

Answer:

cos 78⁰.

Step-by-step explanation:

Use cos 2A = cos^2 A - sin^2 A

so cos^2 39 - sin^2 39 = cos (2*39) = cos 78.

Answer Link

Otras preguntas

what is 67% to 296 this is math
What does (3/5) to the second power equal
what multiples to -60 and adds to -28
what is an integer between the square root of 30 and 4*Pi divided by 3
Most investment returns in the U.S. are currently taxed at a 15% rate. Therefore, investors lose 15% of their returns to pay the cost of taxes. If the governmen
Solve the equation for y. 5x – 7y = 10
How does estimation help you place the decimal point when multiplying
Which of the following qualities are NOT associated with mineral luster? A. dull B. rough surface C. metallic D. opaque
What is the meaning of the Greek root port as it is used in the word comports?
Which of the following qualities are NOT associated with mineral luster? A. dull B. rough surface C. metallic D. opaque