Trignometry questions EASY HELP

1. Which is a solution to the equation below? sin2xsecx=1

2. What is the exact value of cos15 degrees?

3. Which expression is equivalent to the expression below? cos^2 xsin^2?

4. What is the exact value of cos2theta? one side is 8 and the other is 15

5. The angle x lies in quadrant ll. If sinx=3/5, then what is the exact value of tan2x?

  1. 👍 0
  2. 👎 0
  3. 👁 261

    1. 👍 0
    2. 👎 0
  2. This assignment is obviously meant to study the double angle formulas

    sin 2x secx = 1
    2sinxcosx(1/cosx) = 1
    sinx = 1/2
    so x is in I or II
    x = 30 or 150 degrees or pi/6, 5pi/6 radians

    2. use cos2A = 1 - 2cos^2 A
    cos 30 = 1 - 2cos^2 A
    you should know cos 30, sub it in and simplify

    how about you trying some of these.

    1. 👍 0
    2. 👎 0
  3. in #2 I had my formula backwards

    should say

    cos 2A = 2cos^2 A - 1
    cos 30 = 2cos^2 15 - 1

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions


    Solve each equation by graphing the related function. If the equation has no real-number solution, write no solution. NOTE: when I write + it has a minus on the bottom too x^2+7=0 a. x= +7 b. x = +3.5 c. x= 0 d. no solution ***

    asked by a on April 4, 2017
  2. Chemistry

    Which of the following are exact numbers? a. There are 100 cm in 1 m. b. One meter equals 1.094 yard. c. We can use the equation: F=9/5 C + 32 to convert from Celsius to Fahrenheit temperature. Are the numbers 9/5 and 32 exact or

    asked by Dalal on January 27, 2018
  3. Algebra

    Consider the equation 4x^2 – 16x + 25 = 0. (a) Show how to compute the discriminant, b^2 – 4ac, and then state whether there is one real-number solution, two different real-number solutions, or two different imaginary-number

    asked by Pamela on July 7, 2009
  4. Math

    Find the exact solution and a two-decimal-place approximation for it by using the Laws of Logarithms and the Change of Base Formula. 4^(5 − x) = 6 (a) using the Laws of Logarithms exact solution approximate solution (b) using

    asked by LOGS on October 31, 2019
  1. differential equations

    the directions are to determine whether or not the equation is exact if so then solve it. the question is (x-y^3+ysinx)dx = (3xy^2+2ycosx)dy i solve and i got that it is exact because My is -3y^2+2ysinx and Nx is -3y^2+2ysinx

    asked by allison on October 8, 2008
  2. Chemistry

    a solution of HCL is approximately 0.1M and has to be standardized . 1.234g Na2CO3 are dissolved to make 100ml of solution. 20mL of this solution are titrated with the HCL solution, requiring 31.3mL for the second equivalence

    asked by Joshua on January 9, 2015
  3. Algebra

    Solve the logarithmic equation. Be sure to reject any value of x that is not in the domain of the original logarithmic expression. ln ã(x+4)=1 What is the exact solution? Select the correct choice below and, if necessary, fill

    asked by edward on February 3, 2016
  4. algebra 2

    Solve the equation. Give an exact solution. ln(3x - 2) = ln 2 - ln(x - 1)

    asked by sky on July 13, 2011
  1. college algebra

    solve the following exponential equation. 7^x=8 a. x= Write in exact solution b. then with that answer move the decimal 3 points over

    asked by confused on November 27, 2012
  2. algebra

    can you show me how to do these problems solve the equation by finding the exact solution 1/3x-2=2 b) 1/3log(x)-log(100)=2 c)ln(x)-ln(5)=7

    asked by missfubu-c on October 23, 2012
  3. logarithms

    Solve the logarithm equation. Express the solution in exact form only. log[6](64x^3+1)-log[6](4x+1)=1

    asked by Jennifer on January 3, 2012
  4. Algebra

    Solve the equation. Identify any extraneous solutions. √a=-2 A.4 is a solution of the original equation. B.4 is a solution of the original equation. -4 is an extraneous solution***** C.-4 is a solution of the original equation.

    asked by Røse on May 30, 2019

You can view more similar questions or ask a new question.