8 is the hypotenuse and x is the adjacent side to the 60-degree angle. This means that you would need cosine (adjacent over hypotenuse) or secant (hypotenuse over adjacent). Cosine is not an option so it's secant.
sec 60 degrees = 8/x
Next, in a 30 60 90 triangle, you know that the side lengths are 1, 1/2 and sqrt(3)/2. So the secant of 60 degrees is 1 divided by 1/2 which is 2.
So the answer is the first question: x = 4
Answer:
39 km/h
Step-by-step explanation:
Velocity is the rate of change of distance in a given direction with time. Mathematically,
Velocity = Displacement/time
Like speed, velocity is measured in Km/h or m/s.
Given that the car travels at 54 km/h for first 20seconds,
since 60 seconds = 1 minute and
60 minutes = 1 h,
20 seconds
= 20/(60 ×60) h
= 1/180 h
In the same vein,
30 seconds
= 30 / (60 ×60) h
= 1/120 h
10 seconds
= 10/(60 ×60) h
= 1/360 h
Hence if the car travels 54 km/h for 10 seconds, the distance covered
= 54 × 1/180
= 3/10 Km
If the car travels 36km/h for next 30seconds, the distance covered
= 36 × 1/120
= 3/10 Km
If the car travels 18km/h for next 10 seconds, the distance covered
= 18 × 1/360
= 1/20 km
Total distance = 3/10 Km + 3/10 Km + 1/20 Km
= 13/20 Km
Total time spent = 20 + 30 + 10
= 60 seconds
= 1/60 h
Average velocity = 13/20 km/ 1/60 h
= 39 Km/h
So here, you just put in the value inside the parenthesis of the function into the actual function itself.
Here, for h(f(2)), the first one to put in is the one in f, which is 2.
Since f(x) = 3*2^x, and since x here is equal to 2, (because h(f(2)), we can just put in the 2 in place of the x.
3 * 2 ^ 2
And then you get:
3 * 4
Or 12.
So now you have
h(12)
Now do the same thing.
2 * 12 - 7
24 - 7
17
Pythagoras theorem, answer is sqrt69 or 8.307 to 3dp.
