Questions

1. Using the scientific calculator below, find the unknowns in the following:
 

a) sin θ = 1            b) cos(45) = x        c) sin(30) = x        d) cos θ = √3 / 2

2. Find the angle A in the following diagram (figure 10-8):

3. Find x and y from the figure (10 - 9) below:

4. Using the right angle triangle above: (θ = 40)

a) calculate sin θ 

b) calculate cos θ 

c) calculate tan θ 

and finally

d) calculate sinθ / cosθ, what do you notice about the answer? 

e) what can you conclude about tanθ and sinθ / cosθ??  (hopefully this helps you to answer the poll on the left hand side of this page)

Answers: 

Q.1 a) 90,  b) 1/√2 or  0.7071,  c) 0.5 or 1/2  d) 30

Q.2   36.87

Q.3    x = 125.86,  y = 195.81

Q.4 a) 0.6428  b) 0.7660  c) 0.8391  d) 0.8391, it is same as tan θ  e)  they are equal