All 5 Uses

positive
in
Warriors Don't Cry
(Auto-generated)

Three years later, when Grandma discovered I would be one of the first blacks to attend Central High School, she said the nightmare that had surrounded my birth was proof positive that destiny had assigned me a special task.
p. 1.5 *

positive = certain
His positive attitude gave me hope that even if I couldn't speak my truth, the scales of justice were weighted on our side.
p. 56.5

positive = optimistic or agreeable
Even when he was punched with punishing blows or was kicked to the floor, he kept a positive attitude.
p. 131.1 *
All the while I was talking to the reporter, I kept our instructions in mind: Accentuate the positive—don't complain too much.†
p. 87.2
I look back on my Little Rock integration experience as ultimately a positive force that shaped the course of my life.†
p. 222.4

Definitions:

(1) (positive as in: I'm absolutely positive!)
certain (having no doubt; or used for emphasis)
(2) (positive as in: had a positive effect)
good or beneficial
(3) (positive as in: positive feedback from my boss)
approval or agreement
(4) (positive as in: a positive attitude)
optimistic (expecting or focusing on good things); or agreeable
(5) (positive as in: The test came back positive.)
found a condition or substance to be present
indicating the presence of something being tested for -- especially a disease, condition, or substance
(6) (positive as in: a positive number)
greater than zero (of a number)
(7) (meaning too rare to warrant focus)
See a comprehensive dictionary for less common meanings of positive including some in the fields of electricity, physics, chemistry, medicine, philosophy, and grammar. Note that most all senses of positive indicate that something is good or present.