Solving a Trigonometric Equation: v^2*sin(180-2theta2)/g

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Homework Help Overview

The discussion revolves around solving a trigonometric equation involving the expression v^2*sin(180-2theta2)/g. The context includes the use of trigonometric identities and simplifications related to angles.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss substituting angles and simplifying trigonometric expressions. Questions arise about the next steps after substitution and the need to verify the equality of both sides of the equation using identities.

Discussion Status

Some participants have provided guidance on using trigonometric identities to simplify the equation. There is an acknowledgment of the importance of understanding the identities involved, but no explicit consensus or resolution has been reached.

Contextual Notes

Participants mention specific trigonometric identities and their applications, indicating a focus on the foundational concepts necessary for solving the equation. There is an implicit understanding that further simplification is required, but the exact path forward remains open for exploration.

DeltaForce
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Homework Statement
Show that the range of the projectile is the same for two different projection angles --- a pair that add up to 90 degrees.
Relevant Equations
theta1 +theta2 = 90

v^2 * sin(2theta1)/g = v^2 *sin(2theta2)/g
theta1 = 90- theta2
I substituted that into v^2*sin(2theta1)/g
So I get
v^2*sin(180-2theta2)/g

Now I'm stuck. What do I do next?
 
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You need to go back to the equation. You need to show that the 2 sides of the equation are indeed equal, using some trigonometric identities. You may find this list of identities helpful. https://bitly.com/trigiden
 
Ohh... ok. So it has something to do with the sum and difference identities. Thank you.
 
DeltaForce said:
What do I do next
You ought to know how to simplify sin(180-x), sin(90-x), sin(180+x), and likewise with cos.
 
Yeah. I got it with the trig identities.
 

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