ENG6 WQ2016 Lab 1
1. Calculate and then display using the disp() function:
a.
sin(
7𝜋
9
)
𝑐𝑜𝑠2(
5
7
𝜋)
+
1
7
tan (
5
12
𝜋)
b.
tan64°
𝑐𝑜𝑠214°
−
3 sin80°
√0.9
3 +
cos 55°
sin11°
2. Two trigonometric identities are given by:
a. sin 4𝑥 = 4 sin 𝑥 cos 𝑥 − 8𝑠𝑖𝑛3𝑥 cos 𝑥
b. cos 2𝑥 =
1−𝑡𝑎𝑛2𝑥
1+𝑡𝑎𝑛2𝑥
c. For each part, verify that the identity is correct by calculating the values of the left
and right sides of the equation, substituting 𝑥 = 𝜋 9⁄
3. Calculate the length of a in figure 1. (Hint: use law of cosines:
𝑎2 = 𝑏2 + 𝑐2 − 2𝑏𝑐 cos𝛼 )