Alright, lets get started.
Please take a look at the diagram attached.
The reference angle of 75 will be 75
As it is mentioned that the angle intersects the unit circle means r = 1
So, finding cos
cos 75 =
cos 75 =
cos 75 = 0.259 is the Answer
Hope it will help :)
81 a² - 25 is a difference of two squares and its factors are (9a + 5z³) and (9a - 5z³)
Step-by-step explanation:
The difference of two squares is a binomial of two terms each term is a square and the sign between the two terms is (-), its factorization is the product of two identical binomials with different middle signs
∵ The binomial is 81 a² - 25
∵ = 9
∵ = a
∴
∵ = 5
∵ = z³
∴
- The two terms have square root
∵ The sign between them is (-)
∴ 81 a² - 25 is a difference of two squares
∵ Its factorization is two identical brackets with different
middle signs
∵ 81 a² = 9a × 9a
∵ 25 = 5z³ × 5z³
- The terms of the two brackets are 9a and 5z³
∴ 81 a² - 25 = (9a + 5z³)(9a - 5z³)
81 a² - 25 is a difference of two squares and its factors are (9a + 5z³) and (9a - 5z³)
Learn more:
You can learn more about the difference of two squares in brainly.com/question/1414397
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