Easy question help please

Which of the following is the maximum value of the equation y=-x^2+2x+5 a. 5 b. 6 c. 2. d. 1

The pyraminx is a rubik's cube-type toy in the shape of a tetrahedron. the pyraminx shown below has edges 15\,\text{cm}15cm long and vertical height h=12.2\,\text{cm}h=12.2cm. the triangle drawn with dashed lines is a right triangle. what is the distance rr? round your answer to the nearest tenth.

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.