5
If tan θ = —— , calculate the value of cos θ:
4
Recall the definition of the tangent function:
sin θ
tan θ = ————
cos θ
5 sin θ
—— = ————
4 cos θ
Cross multiply:
5 · cos θ = 4 · sin θ
Square both sides:
(5 · cos θ)² = (4 · sin θ)²
5² · cos² θ = 4² · sin² θ
25 · cos² θ = 16 · sin² θ
But sin² θ = 1 – cos² θ. Substitute that for sin² θ into the equation above, then you get
25 · cos² θ = 16 · (1 – cos² θ)
25 · cos² θ = 16 – 16 · cos² θ
Isolate cos² θ:
25 · cos² θ + 16 · cos² θ = 16
(25 + 16) · cos² θ = 16
41 · cos² θ = 16
16
cos² θ = ———
41
4²
cos² θ = ————
(√41)²
Take square root of both sides:
4
cos θ = ± ———
√41
4 4
cos θ = – ——— or cos θ = ——— ✔
√41 √41
The sign of cos θ depends on which quadrant θ lies. Since you first have a positive value for tan θ, then that means θ lies either in the 1st or the 3rd quadrant.
• If θ is a 1st quadrant angle, then
cos θ > 0
4
cos θ = ——— ✔
√41
• If θ is a 3rd quadrant angle, then
cos θ < 0
4
cos θ = – ——— ✔
√41
I hope this helps. =)
X factor because its the u have to run before you fly effect
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Answer:
A 99% confidence interval will be wider than a 95% confidence interval
Step-by-step explanation:
From the question we are told that
The 95% confidence interval for for the mean foot length for students at the college is found to be 21.709 to 25.091 cm
Generally the width of a confidence interval is dependent on the margin of error.
Generally the margin of error is mathematically represented as
From the above equation we see that
Here
is the critical value of the half of the level of significance and this value increase as the confidence level increase
Now if a 99% confidence level is used , it then means that the value of
will increase, this in turn will increase the margin of error and in turn this will increase the width of the confidence interval
Hence a 99% confidence interval will be wider than a 95% confidence interval
?
Step-by-step explanation:
Answer:
the answer is c
Step-by-step explanation:hope this helped!