Can anybody prove with diagram, why for angles having odd multiple of (pi/2) the trigonometrical ratio changes from sin to cos, cos to sin, tan to cot etc..

(urgent ) use pi 3.14 to estimate the circumference of the circle to the nearest hundredth middle is 4in (urgent )

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.

Adriana had a garden where he measured the height of a corn plant. what. on the first day,it was 145 cm tall.after 2 weeks is grew by 23 cm.what is the height of the corn plant