I hope you are looking for these answer choices as you have not posted the choices. Therefore, I have a similar question with these answer choices.
a). tan² x - 1 = sec²x
b). 4 cosxsinx = 2cos + 1 -2sinx
c). tanx cosx cscx = 1
d). 1- tanx tany = cos(x+y) ÷ cosx cosy
<span>Options B, C, D are correct because, for all them, left-hand side equals to the right-hand side for x = 0.
The option A)
</span>tan² x - 1 = sec²x<span> is not true.
since x = 0
Therefore,
The Right hand side would be:
</span>tan² x - 1 = sec²(0)<span>
= 1
The Left hand side would be:
</span> tan² x - 1 = tan² (0) - 1
= 0 - 1
= -2
Therefore,
Both sides are not equal so it's not a trigonometric identity.
Answer:84.375
Step-by-step explanation:
i mean if you by a bike for 200 hundread and every year it goes down by 25% you would just subtract 25 % 3 times ;)
Six hundred fifty five thousand five hundred seventy five
-4.9t²+7.5t+1.8=2.1
-4.9t²+7.5t-0.3=0
t=-7.5±√(56.25-4*-4.9*-.3)/-2*4.9
t=-7.5±√(44.49/-9.8
t=(-7.5±6.67)/-9.8
t=-.83/-9.8 = .085 or t= -14.17/-9.8 = 1.446
