Find the exact values of cos 2x and tan 2x if sin x =4/5 and x is a quadrant II angle.

Step-by-step explanation: 3-4-5 triangle

If sinx = 4/5, then cosx = -3/5 and tanx = 4/-3   x is approximately 126.87°

cos2x = cos²x - sin²x = (-3/5)² - (4/5)² = 9/25 - 16/25 = - 7/25

tan2x = 2tanx / (1 - tan²x) = 2(4/-3) / (1 - (4/-3)²) = (8/-3) / (1 - 16/9) = (-8/3) / (-7/9)

tan2x =  (-8/3) • (-9/7) = 72/21 = 24/7

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step-by-step explanation:

the inequality is:

250c+180g≥950

step-by-step explanation:

let c denotes the number of days in a week   miyoko worked as a cryptographer.

and g denotes the number of days in a week she works as a geologist.

now we are given that she earns $250 for every day she works as a cryptographer,and earns $180 for every day she works as a geologist.

now miyoko's goal is to earn more than $950 this week.

hence, the inequality could be represented as:

250c+180g≥950