Answer:
Step-by-step explanation:
sin²β + sin²β×tan²β = tan²β
sin²β( 1 + tan²β ) = tan²β
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<u><em>sin²β + cos²β = 1 </em></u>
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+ 
= 
⇒ tan²β + 1 = sec²β ⇔ 1 + tan²β = sec²β
~~~~~~~~~~~~~~
1 + tan²β = 
L.H. = sin²β ( ) = tan²β
R.H. = tan²β
30 is the answer
i can help if need be
I think it's 2.2. I apologize if it's incorrect
Answer:
Step-by-step explanation
Let's say d = distance, r = speed and t = time
We know the distance formula is :
distance = speed x time
d = r multiplied by t
d = rt
If the speed is 15km/hr, the time would be 30 minutes shorter.
Since d = rt,
90 = 15t
t = 6,
This means the time taken for the bus to complete the journey at 15km/hr would be 6hrs.
Originally though, the journey takes 30 minutes longer.
So we can say t = 6.5 hrs , and we know d = 90
Now we use the distance formula:
d = rt, since we want to find the original speed, we want to find r.
Speed = distance/time
r = d/t
r = 90/6.5
r = 180/13
Therefore the original speed is 180/13 km/hr
