Establish the identity.cos 3x = cos3 x - 3 sin2 x cos x
What will be an ideal response?
cos 3x = cos (2x + x) = cos 2x cos x - sin 2x sin x = (cos2 x - sin2 x) cos x - 2 sin x cos x sin x = cos3 x - sin2 x cos x - 2 sin2 x cos x = cos3 x - 3 sin2 x cos x.
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In the circuit below, Vin = 7 V, R = 250 ê, xC = 1000 ê, and C = 90 pF. What are the values of VO and I at f1?
a. VO = 4.95 V, I = 19.8 mA
b. VO = 6.21 V, I = 19.8 mA
c. VO = 7.00 V, I = 19.8 mA
d. VO = 5.55 V, I = 22.2 mA
e. VO = 7.00 V, I = 28.0 mA
Use trigonometric identities to find the exact value.
A. 2
B. 
C. 
D. 
Solve.The ratio of the weight of an object on Mars to the weight of an object on Earth is 0.4 to 1. How much will a 160-pound astronaut weigh on Mars?
A. 64 pounds B. 40 pounds C. 250 pounds D. 400 pounds
Solve the inequality.4(0.4)x - 6 ? 14
A. x ? 
B. x ? 
C. x ? 
D. x ? 