Prove that the expression can have only positive values: x^2+2x+2
4x^2-4x+6
a^2+b^2-2ab+1
x^2+y^2+z^2+2xy+5

Please help me!!

In the image, point a marks the center of the circle. which two lengths must form a ratio of 1 : 2? (options are in the images since thought they were harmful phrases)

Can you me find the missing length. i attached an image.

Determine the common ratio and find the next three terms of the geometric sequence. 649-14-02-00-00_files/i0100000, 649-14-02-00-00_files/i0100001, 2, a. 3; 649-14-02-00-00_files/i0100002, 649-14-02-00-00_files/i0100003, 649-14-02-00-00_files/i0100004. c. 649-14-02-00-00_files/i0100005; 649-14-02-00-00_files/i0100006, 649-14-02-00-00_files/i0100007, 649-14-02-00-00_files/i0100008. b. 3; 6, 18, 54 d. 649-14-02-00-00_files/i0100009. 6, 18, 54 select the best answer from the choices provided a b c d