Question

if tan(145) = -1/1.43 , what is tan(-125) A. -1.43, B. 1.43, C. 1/1.43, D. -1/1.43

Answer 1

tan (-125)  = tan 235 =  1.42815
tan 145  = -1/143 = -0.70

1.42815 = -1/-0.70 

so answer is  1.43

Answer 2

Answer:

B. 1.43

Step-by-step explanation:

Because tan (180-θ)=-tan θ

$tan (145) = tan (180 -35)= -tan 35 = -\frac{1}{1.43}\\tan 35 =\frac{1}{1.43}$

Because tan (90+θ) = -cot θ

tan (-125) can be written as:

$tan(-125)=-tan (125) = - tan (90+35) = cot 35$

tan θ x cot θ =1

⇒tan 35 x cot 35 = 1

⇒$\frac{1}{1.43} \times cot 35 =1 \\ cot 35 = 1.43$

⇒$tan(-125)= cot 35 = 1.43$