Answer:
A
Step-by-step explanation:
The formula that relates current, power and resistance is
Where
I is the current (in amperes)
P is the power (in watts)
R is the resistance (in ohms)
We know P = 500 and R = 25, we plug them into the formula and solve for I:
Correct answer is 4.47 Amperes, or choice A.
Answer:
What is the exact value of tan(−π4)? is 20
You can use the identity
cos(x)² +sin(x)² = 1
to find sin(x) from cos(x) or vice versa.
(1/4)² +sin(x)² = 1
sin(x)² = 1 - 1/16
sin(x) = ±(√15)/4
Then the tangent can be computed as the ratio of sine to cosine.
tan(x) = sin(x)/cos(x) = (±(√15)/4)/(1/4)
tan(x) = ±√15
There are two possible answers.
In the first quadrant:
sin(x) = (√15)/4
tan(x) = √15
In the fourth quadrant:
sin(x) = -(√15)/4
tan(x) = -√15
