This revolves around exact trig values - no easy way to say this, you just need to memorise them. They are there for sin cos and tan, but I will give you the main tan ones below - note this is RADIANS (always work in them when you can, everything is better):
tan0: 0
tanpi/6: 1/sqrt(3)
tanpi/4: 1
tanpi/3: sqrt(3)
tanpi/2: undefined
Now we just need to equate -2pi/3 to something we understand. 2pi/3 is 1/3 of the way round a circle, so -2pi/3 is 1/3 of the way round the circle going backwards (anticlockwise), so on a diagram we already know it's in the third quadrant of the circle (somewhere between pi and 3pi/2 rads).
We also know it is pi/3 away from pi, so we are looking at sqrt(3) or -sqrt(3) because of those exact values.
Now we just need to work out if it's positive or negative. You can look up a graph of tan and it'll show that the graph intercepts y at (0,0) and has a period of pi rads. Therefore between pi and 3pi/2 rads, the values of tan are positive. Therefore, this gives us our answer of sqrt(3).
For the first equation, I put it in y=mx+b form, so y=-3x-9
the second one is x=4
hope i helped
If two fractions have the same denominator, the fraction with the larger numerator is the larger number.
Answer:
5 or less
Step-by-step explanation:
The speed increased linearly with distance, but is not decreasing linearly with distance. This suggests the track has an unknown shape, so prediction of car behavior is a guess, at best.
If the car continues to decrease its speed at 3 units per unit distance, then the final 3 units of speed will decrease to 0 in one additional unit of distance. That is, the car will stop at a distance of 5 units.
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Since the car has be decreasing its speed at an increasing rate with respect to distance, very possibly the car will stop before it reaches distance unit 5.
Since we don't know the track shape, it seems possible the car may not stop until some large unknown number of distance units, say 10 or 1000.
Answer:
2x-10+x+x+10=180, or 4x=180
Step-by-step explanation:
So since the total is 180, you add them all up like an equation.
So,
2x-10+x+x+10
Combine like terms
4x=180
x=45
Then plug it back in to the equations.
x=45
(2x-10)=80
(x+10)=55