What is the equation of the midline of the function f(x) = 5.6sin (2.6x - 4.2) - 9.1?

y = -9.1
y = -4.2
y = 4.2
y = 9.1

I think it's D?

Erin bought christmas cards for $2 each to send to her family and friends. which variable is the dependent variable?

Mario is constructing a frame for 10 in. by 8 in. photo. he wants the frame to be the same with all the way around in the same area of the frame and photo to be 120 square inches what is the dimension of the frame?

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap