Which innovative advertising technique did Texas Instruments use in the 1990s to make their graphing calculators essential for math education?

Texas Instruments has been a dominant force in the calculator and educational mathematics technology market for decades. Their marketing strategies and brand positioning have played a crucial role in maintaining their status in mathematics education. This trivia question explores how Texas Instruments used clever advertising to cement their position in the mathematics education sector.

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

They created educational partnerships with textbook publishers to include TI calculator-specific instructions in math textbooks
They hired famous mathematicians as celebrity endorsers for television commercials
They offered lifetime free battery replacements with proof of purchase
They implemented a buy-back program where students could trade in old calculators for newer models at half price