Which equation can be used to find b in the triangle below?
10
tan b - 8/10
tan b- 8/6
cose - 10/6
cose 10/8

Step-by-step explanation:

see the attached figure to better understand the problem

we know that

In the right triangle ABC of the figure

1) The tangent of angle B is equal to divide the opposite side angle B to the adjacent side to angle B

so

substitute the given values

2) The sine of angle B is equal to divide the opposite side angle B to the hypotenuse

substitute the given values

3) The cosine of angle B is equal to divide the adjacent side angle B to the hypotenuse

substitute the given values

therefore

The answer is

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is: