Answer:
Option a. 1C, 2A, 3B, 4D.
Step-by-step explanation:
1) We know that tan(x)=sin(x)/cos(x). If x=0, sin(x)=0 and cos(x)=1 then tan(x)=0. For that reason, we know that the graph passes through the point (0,0).
If x=45, then sin(45)= and cos(45)=
. Thus tan(45)=1. The only graph that passes through the point (0,0) and is possitive when x=45 is the graph C.
2) We know that cot(x)=cos(x)/sin(x). If x=0, sin(x)=0 and cos(x)=1 then tan(x)=+∞. For that reason, we know that the graph has an asymptote in y=0, in other words, it never crosses the y-axis.
If x=45, then sin(45)= and cos(45)=
. Thus cot(45)=1. The only graph that has an asymptote in y=0 and is possitive when x=45 is the graph A.
3) We know that -tan(x)=-sin(x)/cos(x). If x=0, sin(x)=0 and cos(x)=1 then -tan(x)=0. For that reason, we know that the graph passes through the point (0,0).
If x=45, then sin(45)= and cos(45)=
. Thus -tan(45)=-1. The only graph that passes through the point (0,0) and is negative when x=45 is the graph B.
) We know that -cot(x)=-cos(x)/sin(x). If x=0, sin(x)=0 and cos(x)=1 then tan(x)=-∞. For that reason, we know that the graph has an asymptote in y=0, in other words, it never crosses the y-axis.
If x=45, then sin(45)= and cos(45)=
. Thus -cot(45)=-1. The only graph that has an asymptote in y=0 and is negative when x=45 is the graph D.