Keyword Analysis & Research: what does the u symbol mean in math

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
what does the u symbol mean in math	1.19	0.8	453	73	35
what	1.82	0.1	7196	43	4
does	0.68	0.6	5811	50	4
the	0.69	0.1	6593	14	3
u	0.34	0.7	4036	57	1
symbol	0.07	0.3	6339	24	6
mean	1.96	0.9	1703	39	4
in	0.25	1	9960	55	2
math	0.53	0.4	4821	42	4

Keyword	CPC	PCC	Volume	Score
what does the u symbol mean in math	1.69	0.7	6831	75